Implements visual accessibility features for designer and companion. (#2472)

appinventor/appengine/src/com/google/appinventor/client/editor/simple/components/MockButtonBase.java

@@ -8,6 +8,7 @@ package com.google.appinventor.client.editor.simple.components;
 
 import static com.google.appinventor.client.Ode.MESSAGES;
 import com.google.appinventor.client.editor.simple.SimpleEditor;
+import com.google.appinventor.client.editor.youngandroid.YaFormEditor;
 import com.google.appinventor.client.output.OdeLog;
 import com.google.gwt.event.dom.client.ErrorEvent;
 import com.google.gwt.event.dom.client.ErrorHandler;
@@ -24,7 +25,7 @@ import com.google.gwt.user.client.ui.Image;
  *
  * @author lizlooney@google.com (Liz Looney)
  */
-abstract class MockButtonBase extends MockVisibleComponent {
+abstract class MockButtonBase extends MockVisibleComponent implements FormChangeListener {
   // Property names
   private static final String PROPERTY_NAME_IMAGE = "Image";
 
@@ -75,6 +76,19 @@ abstract class MockButtonBase extends MockVisibleComponent {
     deckPanel.add(image);
     deckPanel.showWidget(0);
     initComponent(deckPanel);
+
+  }
+
+  @Override
+  protected void onAttach() {
+    super.onAttach();
+    ((YaFormEditor) editor).getForm().addFormChangeListener(this);
+  }
+
+  @Override
+  protected void onDetach() {
+    super.onDetach();
+    ((YaFormEditor) editor).getForm().removeFormChangeListener(this);
   }
 
   /**
@@ -159,7 +173,12 @@ abstract class MockButtonBase extends MockVisibleComponent {
       return;
     }
     if (MockComponentsUtil.isDefaultColor(text)) {
-      MockComponentsUtil.resetWidgetBackgroundColor(buttonWidget);
+      MockForm form = ((YaFormEditor) editor).getForm();
+      if (form != null && form.getPropertyValue("HighContrast").equals("True")) {
+        MockComponentsUtil.setWidgetBackgroundColor(buttonWidget, "&HFF000000");
+      } else {
+        MockComponentsUtil.resetWidgetBackgroundColor(buttonWidget);
+      }
     } else {
       MockComponentsUtil.setWidgetBackgroundColor(buttonWidget, text);
     }
@@ -192,8 +211,17 @@ abstract class MockButtonBase extends MockVisibleComponent {
    * Sets the button's FontSize property to a new value.
    */
   private void setFontSizeProperty(String text) {
-    MockComponentsUtil.setWidgetFontSize(buttonWidget, text);
-    updatePreferredSizeOfButton();
+    float convertedText = Float.parseFloat(text);
+    if (convertedText == 14.0 || convertedText == 24.0) {
+      MockForm form = ((YaFormEditor) editor).getForm();
+      if (form != null && form.getPropertyValue("BigDefaultText").equals("True")) {
+        MockComponentsUtil.setWidgetFontSize(buttonWidget, "24");
+      } else {
+        MockComponentsUtil.setWidgetFontSize(buttonWidget, "14");
+      }
+    } else {
+      MockComponentsUtil.setWidgetFontSize(buttonWidget, text);
+    }
   }
 
   /*
@@ -242,7 +270,12 @@ abstract class MockButtonBase extends MockVisibleComponent {
    */
   private void setTextColorProperty(String text) {
     if (MockComponentsUtil.isDefaultColor(text)) {
-      MockComponentsUtil.resetWidgetTextColor(buttonWidget);
+      MockForm form = ((YaFormEditor) editor).getForm();
+      if (form != null && form.getPropertyValue("HighContrast").equals("True")) {
+        MockComponentsUtil.setWidgetTextColor(buttonWidget, "&HFFFFFFFF");
+      } else {
+        MockComponentsUtil.resetWidgetTextColor(buttonWidget);
+      }
     } else {
       MockComponentsUtil.setWidgetTextColor(buttonWidget, text);
     }
@@ -320,6 +353,43 @@ abstract class MockButtonBase extends MockVisibleComponent {
       setTextColorProperty(newValue);
     } else if (propertyName.equals(PROPERTY_NAME_BUTTONSHAPE)){
       setShapeProperty(newValue);
+
+    }
+  }
+
+  @Override
+  public void onComponentPropertyChanged(MockComponent component, String propertyName, String propertyValue) {
+    if (component.getType().equals(MockForm.TYPE) && propertyName.equals("HighContrast")) {
+      setBackgroundColorProperty(getPropertyValue(PROPERTY_NAME_BACKGROUNDCOLOR));
+      setTextColorProperty(getPropertyValue(PROPERTY_NAME_TEXTCOLOR));
+      updatePreferredSizeOfButton();
+      refreshForm();
     }
+    else if (component.getType().equals(MockForm.TYPE) && propertyName.equals("BigDefaultText")) {
+      setFontSizeProperty(getPropertyValue(PROPERTY_NAME_FONTSIZE));
+      updatePreferredSizeOfButton();
+      refreshForm();
+    }
+
+    }
+
+  @Override
+  public void onComponentRemoved(MockComponent component, boolean permanentlyDeleted) {
+
+  }
+
+  @Override
+  public void onComponentAdded(MockComponent component) {
+
+  }
+
+  @Override
+  public void onComponentRenamed(MockComponent component, String oldName) {
+
+  }
+
+  @Override
+  public void onComponentSelectionChange(MockComponent component, boolean selected) {
+
   }
 }

appinventor/appengine/src/com/google/appinventor/client/editor/simple/components/MockLabel.java

@@ -8,6 +8,7 @@ package com.google.appinventor.client.editor.simple.components;
 
 import static com.google.appinventor.client.Ode.MESSAGES;
 import com.google.appinventor.client.editor.simple.SimpleEditor;
+import com.google.appinventor.client.editor.youngandroid.YaFormEditor;
 import com.google.gwt.safehtml.shared.SimpleHtmlSanitizer;
 import com.google.gwt.user.client.ui.InlineHTML;
 
@@ -15,7 +16,7 @@ import com.google.gwt.user.client.ui.InlineHTML;
  * Mock Label component.
  *
  */
-public final class MockLabel extends MockVisibleComponent {
+public final class MockLabel extends MockVisibleComponent implements FormChangeListener{
 
   /**
    * Component type name.
@@ -41,8 +42,22 @@ public final class MockLabel extends MockVisibleComponent {
     labelWidget = new InlineHTML();
     labelWidget.setStylePrimaryName("ode-SimpleMockComponent");
     initComponent(labelWidget);
+
   }
 
+  @Override
+  protected void onAttach() {
+    super.onAttach();
+    ((YaFormEditor) editor).getForm().addFormChangeListener(this);
+  }
+
+  @Override
+  protected void onDetach() {
+    super.onDetach();
+    ((YaFormEditor) editor).getForm().removeFormChangeListener(this);
+  }
+
+
   @Override
   public void onCreateFromPalette() {
     // Change label text to component name
@@ -84,7 +99,17 @@ public final class MockLabel extends MockVisibleComponent {
    * Sets the label's FontSize property to a new value.
    */
   private void setFontSizeProperty(String text) {
-    MockComponentsUtil.setWidgetFontSize(labelWidget, text);
+    float convertedText = Float.parseFloat(text);
+    if (convertedText == 14.0 || convertedText == 24.0) {
+      MockForm form = ((YaFormEditor) editor).getForm();
+      if (form != null && form.getPropertyValue("BigDefaultText").equals("True")) {
+        MockComponentsUtil.setWidgetFontSize(labelWidget, "24");
+      } else {
+        MockComponentsUtil.setWidgetFontSize(labelWidget, "14");
+      }
+    } else {
+      MockComponentsUtil.setWidgetFontSize(labelWidget, text);
+    }
   }
 
   /*
@@ -157,4 +182,33 @@ public final class MockLabel extends MockVisibleComponent {
       refreshForm();
     }
   }
+
+
+  @Override
+  public void onComponentPropertyChanged(MockComponent component, String propertyName, String propertyValue) {
+    if (component.getType().equals(MockForm.TYPE) && propertyName.equals("BigDefaultText")) {
+      setFontSizeProperty(getPropertyValue(PROPERTY_NAME_FONTSIZE));
+      refreshForm();
+    }
+  }
+
+  @Override
+  public void onComponentRemoved(MockComponent component, boolean permanentlyDeleted) {
+
+  }
+
+  @Override
+  public void onComponentAdded(MockComponent component) {
+
+  }
+
+  @Override
+  public void onComponentRenamed(MockComponent component, String oldName) {
+
+  }
+
+  @Override
+  public void onComponentSelectionChange(MockComponent component, boolean selected) {
+
+  }
 }

appinventor/appengine/src/com/google/appinventor/client/editor/simple/components/MockPasswordTextBox.java

@@ -11,13 +11,15 @@ import com.google.appinventor.components.common.ComponentConstants;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.ui.PasswordTextBox;
 import com.google.gwt.user.client.ui.Widget;
+import com.google.appinventor.client.editor.youngandroid.YaFormEditor;
+
 
 /**
  * Mock PasswordTextBox component.
  *
  * @author lizlooney@google.com (Liz Looney)
  */
-public final class MockPasswordTextBox extends MockWrapper {
+public final class MockPasswordTextBox extends MockWrapper implements FormChangeListener{
 
   /**
    * Component type name.
@@ -41,7 +43,16 @@ public final class MockPasswordTextBox extends MockWrapper {
     passwordTextBoxWidget.setText("**********");
     initWrapper(passwordTextBoxWidget);
   }
-
+  @Override
+  protected void onAttach() {
+    super.onAttach();
+    ((YaFormEditor) editor).getForm().addFormChangeListener(this);
+  }
+  @Override
+  protected void onDetach() {
+    super.onDetach();
+    ((YaFormEditor) editor).getForm().removeFormChangeListener(this);
+  }
   /**
    * Class that extends PasswordTextBox so we can use a protected constructor.
    *
@@ -81,7 +92,12 @@ public final class MockPasswordTextBox extends MockWrapper {
    */
   private void setBackgroundColorProperty(String text) {
     if (MockComponentsUtil.isDefaultColor(text)) {
-      text = "&HFFFFFFFF";  // white
+      MockForm form = ((YaFormEditor) editor).getForm();
+      if (form != null && form.getPropertyValue("HighContrast").equals("True")) {
+        text = "&HFF000000";  // black
+      } else {
+        text = "&HFFFFFFFF";  // white
+      }
     }
     MockComponentsUtil.setWidgetBackgroundColor(passwordTextBoxWidget, text);
   }
@@ -137,7 +153,13 @@ public final class MockPasswordTextBox extends MockWrapper {
    */
   private void setTextColorProperty(String text) {
     if (MockComponentsUtil.isDefaultColor(text)) {
-      text = "&HFF000000";  // black
+      MockForm form = ((YaFormEditor) editor).getForm();
+      if (form != null && form.getPropertyValue("HighContrast").equals("True")) {
+        text = "&HFFFFFFFF";  // white
+      }
+      else {
+        text = "&HFF000000";  //black
+      }
     }
     MockComponentsUtil.setWidgetTextColor(passwordTextBoxWidget, text);
   }
@@ -173,4 +195,41 @@ public final class MockPasswordTextBox extends MockWrapper {
       setTextColorProperty(newValue);
     }
   }
+
+  @Override
+  public void onComponentPropertyChanged(MockComponent component, String propertyName, String propertyValue) {
+    if (component.getType().equals(MockForm.TYPE) && propertyName.equals("HighContrast")) {
+      setBackgroundColorProperty(getPropertyValue(PROPERTY_NAME_BACKGROUNDCOLOR));
+      setTextColorProperty(getPropertyValue(PROPERTY_NAME_TEXTCOLOR));
+      if (propertyValue.equals("True")){
+        setFontSizeProperty("24");
+        refreshForm();
+
+      }
+      else {
+        setFontSizeProperty("14");
+        refreshForm();
+
+      }
+    }
+  }
+  @Override
+  public void onComponentRemoved(MockComponent component, boolean permanentlyDeleted) {
+
+  }
+
+  @Override
+  public void onComponentAdded(MockComponent component) {
+
+  }
+
+  @Override
+  public void onComponentRenamed(MockComponent component, String oldName) {
+
+  }
+
+  @Override
+  public void onComponentSelectionChange(MockComponent component, boolean selected) {
+
+  }
 }

appinventor/appengine/src/com/google/appinventor/client/editor/simple/components/MockTextBoxBase.java

@@ -8,19 +8,21 @@ package com.google.appinventor.client.editor.simple.components;
 
 import static com.google.appinventor.client.Ode.MESSAGES;
 import com.google.appinventor.client.editor.simple.SimpleEditor;
+import com.google.appinventor.client.editor.youngandroid.YaFormEditor;
 import com.google.appinventor.components.common.ComponentConstants;
 import com.google.gwt.resources.client.ImageResource;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.ui.TextBox;
 import com.google.gwt.user.client.ui.Widget;
 
+
 /**
  * Abstract superclass for textbox based mock components.
  *
  * @author sharon@google.com (Sharon Perl)
  * @author lizlooney@google.com (Liz Looney)
  */
-abstract class MockTextBoxBase extends MockWrapper {
+abstract class MockTextBoxBase extends MockWrapper implements FormChangeListener{
 
   // GWT widget used to mock a Simple TextBox
   private final TextBox textBoxWidget;
@@ -38,6 +40,16 @@ abstract class MockTextBoxBase extends MockWrapper {
     initWrapper(textBoxWidget);
   }
 
+  @Override
+  protected void onAttach() {
+        super.onAttach();
+        ((YaFormEditor) editor).getForm().addFormChangeListener(this);
+  }
+  @Override
+  protected void onDetach() {
+        super.onDetach();
+        ((YaFormEditor) editor).getForm().removeFormChangeListener(this);
+  }
   /**
    * Class that extends TextBox so we can use a protected constructor.
    *
@@ -84,7 +96,12 @@ abstract class MockTextBoxBase extends MockWrapper {
    */
   private void setBackgroundColorProperty(String text) {
     if (MockComponentsUtil.isDefaultColor(text)) {
-      text = "&HFFFFFFFF";  // white
+      MockForm form = ((YaFormEditor) editor).getForm();
+      if (form != null && form.getPropertyValue("HighContrast").equals("True")) {
+        text = "&HFF000000";  //black
+      } else {
+        text = "&HFFFFFFFF";  // white
+      }
     }
     MockComponentsUtil.setWidgetBackgroundColor(textBoxWidget, text);
   }
@@ -116,7 +133,17 @@ abstract class MockTextBoxBase extends MockWrapper {
    * Sets the textbox's FontSize property to a new value.
    */
   private void setFontSizeProperty(String text) {
-    MockComponentsUtil.setWidgetFontSize(textBoxWidget, text);
+    float convertedText = Float.parseFloat(text);
+    if (convertedText == 14.0 || convertedText == 24.0) {
+      MockForm form = ((YaFormEditor) editor).getForm();
+      if (form != null && form.getPropertyValue("BigDefaultText").equals("True")) {
+        MockComponentsUtil.setWidgetFontSize(textBoxWidget, "24");
+      } else {
+        MockComponentsUtil.setWidgetFontSize(textBoxWidget, "14");
+      }
+    } else {
+      MockComponentsUtil.setWidgetFontSize(textBoxWidget, text);
+    }
     updatePreferredSize();
   }
 
@@ -148,13 +175,23 @@ abstract class MockTextBoxBase extends MockWrapper {
    */
   private void setTextColorProperty(String text) {
     if (MockComponentsUtil.isDefaultColor(text)) {
-      text = "&HFF000000";  // black
+      MockForm form = ((YaFormEditor) editor).getForm();
+      if (form != null && form.getPropertyValue("HighContrast").equals("True")) {
+        text = "&HFFFFFFFF";  // white
+      } else {
+        text = "&HFF000000";  //black
+
+      }
+
     }
+
     MockComponentsUtil.setWidgetTextColor(textBoxWidget, text);
+
   }
 
   // PropertyChangeListener implementation
 
+
   @Override
   public void onPropertyChange(String propertyName, String newValue) {
     super.onPropertyChange(propertyName, newValue);
@@ -187,4 +224,40 @@ abstract class MockTextBoxBase extends MockWrapper {
       setTextColorProperty(newValue);
     }
   }
+
+  @Override
+  public void onComponentPropertyChanged(MockComponent component, String propertyName, String propertyValue) {
+    if (component.getType().equals(MockForm.TYPE) && propertyName.equals("HighContrast")) {
+      setBackgroundColorProperty(getPropertyValue(PROPERTY_NAME_BACKGROUNDCOLOR));
+      setTextColorProperty(getPropertyValue(PROPERTY_NAME_TEXTCOLOR));
+      //setFontSizeProperty(getPropertyValue(PROPERTY_NAME_FONTSIZE));
+      updatePreferredSize();
+      refreshForm();
+    }
+    else if (component.getType().equals(MockForm.TYPE) && propertyName.equals("BigDefaultText")) {
+      setFontSizeProperty(getPropertyValue(PROPERTY_NAME_FONTSIZE));
+      updatePreferredSize();
+      refreshForm();
+    }
+  }
+
+  @Override
+  public void onComponentRemoved(MockComponent component, boolean permanentlyDeleted) {
+
+  }
+
+  @Override
+  public void onComponentAdded(MockComponent component) {
+
+  }
+
+  @Override
+  public void onComponentRenamed(MockComponent component, String oldName) {
+
+  }
+
+  @Override
+  public void onComponentSelectionChange(MockComponent component, boolean selected) {
+
+  }
 }

appinventor/appengine/src/com/google/appinventor/client/editor/simple/components/MockToggleBase.java

@@ -6,10 +6,13 @@
 package com.google.appinventor.client.editor.simple.components;
 
 import com.google.appinventor.client.editor.simple.SimpleEditor;
+import com.google.appinventor.client.editor.youngandroid.YaFormEditor;
 import com.google.gwt.resources.client.ImageResource;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.ui.Widget;
 
+import java.text.Normalizer;
+
 import static com.google.appinventor.client.Ode.MESSAGES;
 
 /**
@@ -17,7 +20,7 @@ import static com.google.appinventor.client.Ode.MESSAGES;
  *
  * @author srlane@mit.edu (Susan Rati Lane)
  */
-abstract class MockToggleBase<T extends Widget> extends MockWrapper {
+abstract class MockToggleBase<T extends Widget> extends MockWrapper implements FormChangeListener {
 
   // Set toggle widget in child classes
   protected T toggleWidget;
@@ -85,8 +88,19 @@ abstract class MockToggleBase<T extends Widget> extends MockWrapper {
    * Sets the toggle's FontSize property to a new value.
    */
   protected void setFontSizeProperty(String text) {
-    MockComponentsUtil.setWidgetFontSize(toggleWidget, text);
+    float convertedText = Float.parseFloat(text);
+    if (convertedText == 14.0 || convertedText == 24.0) {
+      MockForm form = ((YaFormEditor) editor).getForm();
+      if (form != null && form.getPropertyValue("BigDefaultText").equals("True")) {
+        MockComponentsUtil.setWidgetFontSize(toggleWidget, "24");
+      } else {
+        MockComponentsUtil.setWidgetFontSize(toggleWidget, "14");
+      }
+    } else {
+      MockComponentsUtil.setWidgetFontSize(toggleWidget, text);
+    }
     updatePreferredSize();
+
   }
 
   /*
@@ -145,4 +159,32 @@ abstract class MockToggleBase<T extends Widget> extends MockWrapper {
     preferredSize = MockComponentsUtil
         .getPreferredSizeOfElement(DOM.clone(toggleWidget.getElement(), true));
   }
+
+  @Override
+  public void onComponentPropertyChanged(MockComponent component, String propertyName, String propertyValue) {
+    if (component.getType().equals(MockForm.TYPE) && propertyName.equals("BigDefaultText")) {
+      setFontSizeProperty(getPropertyValue(PROPERTY_NAME_FONTSIZE));
+      refreshForm();
+    }
+  }
+
+  @Override
+  public void onComponentRemoved(MockComponent component, boolean permanentlyDeleted) {
+
+  }
+
+  @Override
+  public void onComponentAdded(MockComponent component) {
+
+  }
+
+  @Override
+  public void onComponentRenamed(MockComponent component, String oldName) {
+
+  }
+
+  @Override
+  public void onComponentSelectionChange(MockComponent component, boolean selected) {
+
+  }
 }

appinventor/appengine/src/com/google/appinventor/client/youngandroid/YoungAndroidFormUpgrader.java

@@ -1051,6 +1051,11 @@ public final class YoungAndroidFormUpgrader {
       srcCompVersion = 27;
     }
 
+    if (srcCompVersion < 28) {
+      // HighContrast and BigDefaultText properties were added.
+      srcCompVersion = 28;
+    }
+
     return srcCompVersion;
   }
 
@@ -1114,6 +1119,10 @@ public final class YoungAndroidFormUpgrader {
      // The Clickable property was added.
      srcCompVersion = 4;
     }
+    if (srcCompVersion < 5) {
+      // The AlternateText property was added.
+      srcCompVersion = 5;
+    }
     return srcCompVersion;
   }
 

appinventor/blocklyeditor/src/versioning.js

@@ -1606,7 +1606,10 @@ Blockly.Versioning.AllUpgradeMaps =
 
     // Click event was added
     // The Clickable property was added.
-    4: "noUpgrade"
+    4: "noUpgrade",
+
+    // AlternateText property was added.
+    5: "noUpgrade"
 
   }, // End Image upgraders
 
@@ -2366,7 +2369,11 @@ Blockly.Versioning.AllUpgradeMaps =
 
     // For FORM_COMPONENT_VERSION 27:
     // - Platform and PlatformVersion read-only blocks were added
-    27: "noUpgrade"
+    27: "noUpgrade",
+
+    // For FORM_COMPONENT_VERSION 28:
+    // - HighContrast and BigDefaultText properties were added
+    28: "noUpgrade"
 
 
   }, // End Screen

appinventor/components/src/com/google/appinventor/components/common/YaVersion.java

@@ -898,7 +898,10 @@ public class YaVersion {
   // - Updated the default value of ShowListsAsJson from false -> true
   // For FORM_COMPONENT_VERSION 27:
   // - Added the Platform and PlatformVersion read-only blocks
-  public static final int FORM_COMPONENT_VERSION = 27;
+  // For FORM_COMPONENT_VERSION 28:
+  // - Added the AlternateText property
+  // - Added the BigDefaultText property
+  public static final int FORM_COMPONENT_VERSION = 28;
 
   // For FUSIONTABLESCONTROL_COMPONENT_VERSION 2:
   // - The Fusiontables API was migrated from SQL to V1
@@ -931,7 +934,9 @@ public class YaVersion {
   // For IMAGE_COMPONENT_VERSION 4:
   // - The Click event was added.
   // - The Clickable property was added.
-  public static final int IMAGE_COMPONENT_VERSION = 4;
+  // For IMAGE_COMPONENT_VERSION 5:
+  // - The AlternateText property was added.
+  public static final int IMAGE_COMPONENT_VERSION = 5;
 
   // For IMAGEPICKER_COMPONENT_VERSION 2:
   // - The Alignment property was renamed to TextAlignment.

appinventor/components/src/com/google/appinventor/components/runtime/AccessibleComponent.java

+// -*- mode: java; c-basic-offset: 2; -*-
+// Copyright 2020-2021 MIT, All rights reserved
+// Released under the Apache License, Version 2.0
+// http://www.apache.org/licenses/LICENSE-2.0
+
+package com.google.appinventor.components.runtime;
+
+public interface AccessibleComponent {
+
+    //Sets the high contrast field of a component to be either True or False
+    void setHighContrast(boolean isHighContrast);
+
+    //Returns whether a component is in high contrast mode or not
+    boolean getHighContrast();
+
+    //Sets the large font field of a component to be either True or False
+    void setLargeFont(boolean isLargeFont);
+
+    //Returns whether a component is in large font mode or not
+    boolean getLargeFont();
+}

appinventor/components/src/com/google/appinventor/components/runtime/ButtonBase.java

@@ -45,7 +45,7 @@ import java.io.IOException;
 @SimpleObject
 @UsesPermissions(permissionNames = "android.permission.INTERNET")
 public abstract class ButtonBase extends AndroidViewComponent
-    implements OnClickListener, OnFocusChangeListener, OnLongClickListener, View.OnTouchListener {
+    implements OnClickListener, OnFocusChangeListener, OnLongClickListener, View.OnTouchListener, AccessibleComponent {
 
   private static final String LOG_TAG = "ButtonBase";
 
@@ -103,6 +103,12 @@ public abstract class ButtonBase extends AndroidViewComponent
   // could not be loaded, this is null.
   private Drawable backgroundImageDrawable;
 
+  //Whether or not the button is in high contrast mode
+  private boolean isHighContrast = false;
+
+  //Whether or not the button is in big text mode
+  private boolean isBigText = false;
+
   /**
    * The minimum width of a button for the current theme.
    *
@@ -158,6 +164,9 @@ public abstract class ButtonBase extends AndroidViewComponent
     Shape(Component.BUTTON_SHAPE_DEFAULT);
   }
 
+  public void Initialize(){
+    updateAppearance();
+  }
     /**
      * If a custom background images is specified for the button, then it will lose the pressed
      * and disabled image effects; no visual feedback.
@@ -343,7 +352,6 @@ public abstract class ButtonBase extends AndroidViewComponent
 
     // Clear the prior background image.
     backgroundImageDrawable = null;
-
     // Load image from file.
     if (imagePath.length() > 0) {
       try {
@@ -402,7 +410,15 @@ public abstract class ButtonBase extends AndroidViewComponent
         if (backgroundColor == Component.COLOR_DEFAULT) {
           // If there is no background image and color is default,
           // restore original 3D bevel appearance.
-          ViewUtil.setBackgroundDrawable(view, defaultButtonDrawable);
+          if (isHighContrast || container.$form().HighContrast()) {
+            ViewUtil.setBackgroundDrawable(view, null);
+            ViewUtil.setBackgroundDrawable(view, getSafeBackgroundDrawable());
+            view.getBackground().setColorFilter(Component.COLOR_BLACK, PorterDuff.Mode.SRC_ATOP);
+          }
+          else {
+            ViewUtil.setBackgroundDrawable(view, defaultButtonDrawable);
+          }
+
         } else if (backgroundColor == Component.COLOR_NONE) {
           // Clear the background image.
           ViewUtil.setBackgroundDrawable(view, null);
@@ -490,7 +506,11 @@ public abstract class ButtonBase extends AndroidViewComponent
       view.getBackground().setColorFilter(backgroundColor, PorterDuff.Mode.CLEAR);
     }
     else if (backgroundColor == Component.COLOR_DEFAULT) {
-      view.getBackground().setColorFilter(SHAPED_DEFAULT_BACKGROUND_COLOR, PorterDuff.Mode.SRC_ATOP);
+      if (isHighContrast || container.$form().HighContrast()) {
+        view.getBackground().setColorFilter(Component.COLOR_BLACK, PorterDuff.Mode.SRC_ATOP);
+      } else {
+        view.getBackground().setColorFilter(SHAPED_DEFAULT_BACKGROUND_COLOR, PorterDuff.Mode.SRC_ATOP);
+      }
     }
     else {
       view.getBackground().setColorFilter(backgroundColor, PorterDuff.Mode.SRC_ATOP);
@@ -638,7 +658,17 @@ public abstract class ButtonBase extends AndroidViewComponent
   @SimpleProperty(
       category = PropertyCategory.APPEARANCE)
   public void FontSize(float size) {
-    TextViewUtil.setFontSize(view, size);
+    if (Math.abs(size-Component.FONT_DEFAULT_SIZE)<.01 || Math.abs(size-24)<.01) {
+      if (container.$form().BigDefaultText()) {
+        TextViewUtil.setFontSize(view, 24);
+      }
+      else {
+        TextViewUtil.setFontSize(view, Component.FONT_DEFAULT_SIZE);
+      }
+    }
+    else {
+      TextViewUtil.setFontSize(view, size);
+    }
   }
 
   /**
@@ -729,7 +759,12 @@ public abstract class ButtonBase extends AndroidViewComponent
     if (argb != Component.COLOR_DEFAULT) {
       TextViewUtil.setTextColor(view, argb);
     } else {
-      TextViewUtil.setTextColors(view, defaultColorStateList);
+      if (isHighContrast || container.$form().HighContrast()){
+        TextViewUtil.setTextColor(view, Color.WHITE);
+      }
+      else {
+        TextViewUtil.setTextColors(view, defaultColorStateList);
+      }
     }
   }
 
@@ -768,4 +803,48 @@ public abstract class ButtonBase extends AndroidViewComponent
     return longClick();
   }
 
+  @Override
+  public void setHighContrast(boolean isHighContrast) {
+    //background of button
+    if (backgroundImageDrawable == null && shape == Component.BUTTON_SHAPE_DEFAULT && backgroundColor == Component.COLOR_DEFAULT) {
+      if (isHighContrast) {
+        ViewUtil.setBackgroundDrawable(view, null);
+        ViewUtil.setBackgroundDrawable(view, getSafeBackgroundDrawable());
+        view.getBackground().setColorFilter(Component.COLOR_BLACK, PorterDuff.Mode.SRC_ATOP);
+      } else {
+        ViewUtil.setBackgroundDrawable(view, defaultButtonDrawable);
+      }
+    }
+
+    //color of text
+    if (textColor == Component.COLOR_DEFAULT) {
+      if (isHighContrast) {
+        TextViewUtil.setTextColor(view, Color.WHITE);
+      } else {
+        TextViewUtil.setTextColors(view, defaultColorStateList);
+      }
+    }
+  }
+
+  @Override
+  public boolean getHighContrast() {
+    return isHighContrast;
+  }
+
+  @Override
+  public void setLargeFont(boolean isLargeFont) {
+    if (TextViewUtil.getFontSize(view, container.$context()) == 24.0 || TextViewUtil.getFontSize(view, container.$context()) == Component.FONT_DEFAULT_SIZE) {
+      if (isLargeFont) {
+        TextViewUtil.setFontSize(view, 24);
+      } else {
+        TextViewUtil.setFontSize(view, Component.FONT_DEFAULT_SIZE);
+      }
+    }
+  }
+
+  @Override
+  public boolean getLargeFont() {
+    return isBigText;
+  }
+
 }

appinventor/components/src/com/google/appinventor/components/runtime/Canvas.java

@@ -886,6 +886,11 @@ public final class Canvas extends AndroidViewComponent implements ComponentConta
     throw new UnsupportedOperationException("Canvas.$add() called");
   }
 
+  @Override
+  public List<? extends Component> getChildren(){
+    return sprites;
+  }
+
   @Override
   public void setChildWidth(AndroidViewComponent component, int width) {
     throw new UnsupportedOperationException("Canvas.setChildWidth() called");

appinventor/components/src/com/google/appinventor/components/runtime/ComponentContainer.java

@@ -8,6 +8,8 @@ package com.google.appinventor.components.runtime;
 
 import android.app.Activity;
 
+import java.util.List;
+
 /**
  * Components that can contain other components need to implement this
  * interface.
@@ -44,6 +46,8 @@ public interface ComponentContainer {
 
   void setChildHeight(AndroidViewComponent component, int height);
 
+  List<? extends Component> getChildren();
+
   int Width();
 
   int Height();

appinventor/components/src/com/google/appinventor/components/runtime/Form.java

@@ -142,6 +142,8 @@ public class Form extends AppInventorCompatActivity
   private static final int DEFAULT_ACCENT_COLOR =
       hexStringToInt(ComponentConstants.DEFAULT_ACCENT_COLOR);
 
+  private List<Component> allChildren = new ArrayList<>();
+
   // Keep track of the current form object.
   // activeForm always holds the Form that is currently handling event dispatching so runtime.scm
   // can lookup symbols in the correct environment.
@@ -203,6 +205,9 @@ public class Form extends AppInventorCompatActivity
   private FrameLayout frameLayout;
   private boolean scrollable;
 
+  private boolean highContrast;
+  private boolean bigDefaultText;
+
   private ScaledFrameLayout scaleLayout;
   private static boolean sCompatibilityMode;
 
@@ -261,6 +266,8 @@ public class Form extends AppInventorCompatActivity
   // FragmentActivity is added in future.
   public static final int MAX_PERMISSION_NONCE = 100000;
 
+
+
   public static class PercentStorageRecord {
     public enum Dim {
       HEIGHT, WIDTH };
@@ -446,6 +453,8 @@ public class Form extends AppInventorCompatActivity
       ActionBar(themeHelper.hasActionBar());
     }
     Scrollable(false);       // frameLayout is created in Scrollable()
+    HighContrast(false);
+    BigDefaultText(false);
     Sizing("Responsive");    // Note: Only the Screen1 value is used as this is per-project
     AboutScreen("");
     BackgroundImage("");
@@ -1118,6 +1127,83 @@ public class Form extends AppInventorCompatActivity
     });
   }
 
+
+  /**
+   * HighContrast property getter method.
+   *
+   * @return  true if we want high constrast mode
+   */
+  @SimpleProperty(category = PropertyCategory.APPEARANCE,
+          description = "When checked, we will use high contrast mode")
+  public boolean HighContrast() {
+    return highContrast;
+  }
+
+  /**
+   * When checked, there will be high contrast mode turned on.
+   *
+   * @param highContrast  true if the high contrast mode is on
+   */
+  @DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_BOOLEAN,
+          defaultValue = "False")
+  @SimpleProperty
+  public void HighContrast(boolean highContrast) {
+
+    //this.scrollable = scrollable;
+    this.highContrast=highContrast;
+    setHighContrastRecursive(this, highContrast);
+    recomputeLayout();
+  }
+
+  private static void setHighContrastRecursive(ComponentContainer container, boolean enabled) {
+    for (Component child : container.getChildren()) {
+      if (child instanceof ComponentContainer) {
+        setHighContrastRecursive((ComponentContainer) child, enabled);
+      } else if (child instanceof AccessibleComponent) {
+        ((AccessibleComponent) child).setHighContrast(enabled);
+      }
+    }
+  }
+
+
+  /**
+   * BigDefaultText property getter method.
+   *
+   * @return  true if we are in the big text mode
+   */
+  @SimpleProperty(category = PropertyCategory.APPEARANCE,
+          description = "When checked, we will use high contrast mode")
+  public boolean BigDefaultText() {
+    return bigDefaultText;
+  }
+
+  /**
+   * When checked, all default size text will be increased in size.
+   *
+   * @param bigDefaultText  true if the big text mode is on
+   */
+  @DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_BOOLEAN,
+          defaultValue = "False")
+  @SimpleProperty
+  public void BigDefaultText(boolean bigDefaultText) {
+
+    //this.scrollable = scrollable;
+    this.bigDefaultText=bigDefaultText;
+    setBigDefaultTextRecursive(this, bigDefaultText);
+    recomputeLayout();
+  }
+
+
+  private static void setBigDefaultTextRecursive(ComponentContainer container, boolean enabled) {
+    for (Component child : container.getChildren()) {
+      if (child instanceof ComponentContainer) {
+        setBigDefaultTextRecursive((ComponentContainer) child, enabled);
+      } else if (child instanceof AccessibleComponent) {
+        ((AccessibleComponent) child).setLargeFont(enabled);
+      }
+    }
+  }
+
   /**
    * Scrollable property getter method.
    *
@@ -2113,9 +2199,18 @@ public class Form extends AppInventorCompatActivity
 
   @Override
   public void $add(AndroidViewComponent component) {
+
     viewLayout.add(component);
+    allChildren.add(component);
+  }
+
+  @Override
+  public List<? extends Component> getChildren(){
+    return allChildren;
   }
 
+
+
   public float deviceDensity(){
     return this.deviceDensity;
   }

appinventor/components/src/com/google/appinventor/components/runtime/HVArrangement.java

@@ -35,6 +35,8 @@ import com.google.appinventor.components.runtime.util.MediaUtil;
 import com.google.appinventor.components.runtime.util.ViewUtil;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * A container for components that arranges them linearly, either
@@ -67,6 +69,9 @@ public class HVArrangement extends AndroidViewComponent implements Component, Co
   // Image path
   private String imagePath = "";
 
+  //list of component children
+  private List<Component> allChildren = new ArrayList<>();
+
   private Drawable defaultButtonDrawable;
 
   private final Handler androidUIHandler = new Handler();
@@ -144,6 +149,12 @@ public class HVArrangement extends AndroidViewComponent implements Component, Co
   @Override
   public void $add(AndroidViewComponent component) {
     viewLayout.add(component);
+    allChildren.add(component);
+  }
+
+  @Override
+  public List<? extends Component> getChildren() {
+    return allChildren;
   }
 
   @Override

appinventor/components/src/com/google/appinventor/components/runtime/Image.java

@@ -88,6 +88,12 @@ public final class Image extends AndroidViewComponent {
     return view;
   }
 
+  @DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_STRING, defaultValue = "")
+  @SimpleProperty(description = "A written description of what the image looks like.")
+  public void AlternateText(String description){
+    view.setContentDescription(description);
+  }
+
   @SimpleEvent(description = "An event that occurs when an image is clicked.")
   public void Click() {
     EventDispatcher.dispatchEvent(this, "Click");

appinventor/components/src/com/google/appinventor/components/runtime/Label.java

@@ -37,7 +37,7 @@ import android.widget.TextView;
     "the appearance and placement of the text.",
     category = ComponentCategory.USERINTERFACE)
 @SimpleObject
-public final class Label extends AndroidViewComponent {
+public final class Label extends AndroidViewComponent implements AccessibleComponent{
 
   // default margin around a label in DPs
   // note that the spacing between adjacent labels will be twice this value
@@ -79,6 +79,9 @@ public final class Label extends AndroidViewComponent {
   // HTML content of the label
   private String htmlContent;
 
+  //Whether or not the text should be big
+  private boolean isBigText = false;
+
   /**
    * Creates a new Label component.
    *
@@ -312,7 +315,18 @@ private void setLabelMargins(boolean hasMargins) {
       defaultValue = Component.FONT_DEFAULT_SIZE + "")
   @SimpleProperty
   public void FontSize(float size) {
-    TextViewUtil.setFontSize(view, size);
+
+    if (Math.abs(size-Component.FONT_DEFAULT_SIZE)<.01 || Math.abs(size-24)<.01) {
+      if (isBigText || container.$form().BigDefaultText()) {
+        TextViewUtil.setFontSize(view, 24);
+      }
+      else {
+        TextViewUtil.setFontSize(view, Component.FONT_DEFAULT_SIZE);
+      }
+    }
+    else {
+      TextViewUtil.setFontSize(view, size);
+    }
   }
 
   /**
@@ -457,4 +471,30 @@ private void setLabelMargins(boolean hasMargins) {
       TextViewUtil.setTextColor(view, container.$form().isDarkTheme() ? Component.COLOR_WHITE : Component.COLOR_BLACK);
     }
   }
+
+  @Override
+  public void setHighContrast(boolean isHighContrast) {
+
+  }
+
+  @Override
+  public boolean getHighContrast() {
+    return false;
+  }
+
+  @Override
+  public void setLargeFont(boolean isLargeFont) {
+    if (TextViewUtil.getFontSize(view, container.$context()) == 24.0 || TextViewUtil.getFontSize(view, container.$context()) == Component.FONT_DEFAULT_SIZE) {
+      if (isLargeFont) {
+        TextViewUtil.setFontSize(view, 24);
+      } else {
+        TextViewUtil.setFontSize(view, Component.FONT_DEFAULT_SIZE);
+      }
+    }
+  }
+
+  @Override
+  public boolean getLargeFont() {
+    return isBigText;
+  }
 }

appinventor/components/src/com/google/appinventor/components/runtime/MapFeatureContainerBase.java

@@ -328,6 +328,11 @@ public abstract class MapFeatureContainerBase extends AndroidViewComponent imple
     throw new UnsupportedOperationException("Map.$add() called");
   }
 
+  @Override
+  public List<? extends Component> getChildren(){
+    return features;
+  }
+
   @Override
   public void setChildWidth(AndroidViewComponent component, int width) {
     throw new UnsupportedOperationException("Map.setChildWidth called");

appinventor/components/src/com/google/appinventor/components/runtime/TableArrangement.java

@@ -18,6 +18,9 @@ import com.google.appinventor.components.runtime.util.ViewUtil;
 import android.app.Activity;
 import android.view.View;
 
+import java.util.ArrayList;
+import java.util.List;
+
 /**
  * Use a table arrangement component to display a group of components in a tabular fashion.
  *
@@ -54,6 +57,8 @@ public class TableArrangement extends AndroidViewComponent
   // Layout
   private final TableLayout viewLayout;
 
+  private List<Component> allChildren;
+
   /**
    * Creates a new TableArrangement component.
    *
@@ -127,6 +132,12 @@ public class TableArrangement extends AndroidViewComponent
   @Override
   public void $add(AndroidViewComponent component) {
     viewLayout.add(component);
+    allChildren.add(component);
+  }
+
+  @Override
+  public List<? extends Component> getChildren(){
+    return allChildren = new ArrayList<>();
   }
 
   @Override

appinventor/components/src/com/google/appinventor/components/runtime/TextBoxBase.java

@@ -6,6 +6,8 @@
 
 package com.google.appinventor.components.runtime;
 
+import android.graphics.Color;
+import android.graphics.PorterDuff;
 import com.google.appinventor.components.annotations.DesignerProperty;
 import com.google.appinventor.components.annotations.IsColor;
 import com.google.appinventor.components.annotations.PropertyCategory;
@@ -35,7 +37,7 @@ import android.widget.EditText;
 
 @SimpleObject
 public abstract class TextBoxBase extends AndroidViewComponent
-    implements OnFocusChangeListener {
+    implements OnFocusChangeListener, AccessibleComponent {
 
   protected final EditText view;
 
@@ -63,6 +65,15 @@ public abstract class TextBoxBase extends AndroidViewComponent
   // This is our handle on Android's nice 3-d default textbox.
   private Drawable defaultTextBoxDrawable;
 
+  //Whether or not the button is in high contrast mode
+  private boolean isHighContrast = false;
+
+  //Whether or not the button is in big text mode
+  private boolean isBigText = false;
+
+  //The default text color of the textbox hint, according to theme
+  private int hintColorDefault;
+
   /**
    * Creates a new TextBoxBase component
    *
@@ -72,6 +83,7 @@ public abstract class TextBoxBase extends AndroidViewComponent
   public TextBoxBase(ComponentContainer container, EditText textview) {
     super(container);
     view = textview;
+    hintColorDefault = view.getCurrentHintTextColor();
     // There appears to be an issue where, by default, Android 7+
     // wants to provide suggestions in text boxes. However, we do not
     // compile the necessary layouts for this to work correctly, which
@@ -104,14 +116,21 @@ public abstract class TextBoxBase extends AndroidViewComponent
     // only). Maybe we need another color value which would be 'SYSTEM_DEFAULT' which
     // will not attempt to explicitly initialize with any of the properties with any
     // particular value.
-    // BackgroundColor(Component.COLOR_NONE);
     Enabled(true);
     fontTypeface = Component.TYPEFACE_DEFAULT;
     TextViewUtil.setFontTypeface(view, fontTypeface, bold, italic);
     FontSize(Component.FONT_DEFAULT_SIZE);
     Hint("");
+    if (isHighContrast || container.$form().HighContrast()) {
+      view.setHintTextColor(COLOR_YELLOW);
+    }
+    else {
+      view.setHintTextColor(hintColorDefault);
+    }
+
     Text("");
     TextColor(Component.COLOR_DEFAULT);
+    BackgroundColor(Component.COLOR_DEFAULT);
   }
 
   @Override
@@ -220,7 +239,11 @@ public abstract class TextBoxBase extends AndroidViewComponent
     if (argb != Component.COLOR_DEFAULT) {
       TextViewUtil.setBackgroundColor(view, argb);
     } else {
-      ViewUtil.setBackgroundDrawable(view, defaultTextBoxDrawable);
+      if (isHighContrast || container.$form().$form().HighContrast()) {
+        TextViewUtil.setBackgroundColor(view, Component.COLOR_BLACK);
+      } else {
+        ViewUtil.setBackgroundDrawable(view, defaultTextBoxDrawable);
+      }
     }
   }
 
@@ -335,7 +358,17 @@ public abstract class TextBoxBase extends AndroidViewComponent
       defaultValue = Component.FONT_DEFAULT_SIZE + "")
   @SimpleProperty
   public void FontSize(float size) {
-    TextViewUtil.setFontSize(view, size);
+    if (Math.abs(size-Component.FONT_DEFAULT_SIZE)<.01 || Math.abs(size-24)<.01) {
+      if (container.$form().BigDefaultText()) {
+        TextViewUtil.setFontSize(view, 24);
+      }
+      else {
+        TextViewUtil.setFontSize(view, Component.FONT_DEFAULT_SIZE);
+      }
+    }
+    else {
+      TextViewUtil.setFontSize(view, size);
+    }
   }
 
   /**
@@ -456,14 +489,19 @@ public abstract class TextBoxBase extends AndroidViewComponent
    * @param argb  text RGB color with alpha
    */
   @DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_COLOR,
-      defaultValue = Component.DEFAULT_VALUE_COLOR_BLACK)
+      defaultValue = Component.DEFAULT_VALUE_COLOR_DEFAULT)
   @SimpleProperty
   public void TextColor(int argb) {
     textColor = argb;
     if (argb != Component.COLOR_DEFAULT) {
       TextViewUtil.setTextColor(view, argb);
     } else {
-      TextViewUtil.setTextColor(view, container.$form().isDarkTheme() ? COLOR_WHITE : Component.COLOR_BLACK);
+      if (isHighContrast || container.$form().HighContrast()) {
+        TextViewUtil.setTextColor(view, COLOR_WHITE);
+      }
+      else {
+        TextViewUtil.setTextColor(view, container.$form().isDarkTheme() ? COLOR_WHITE : Component.COLOR_BLACK);
+      }
     }
   }
 
@@ -491,4 +529,52 @@ public abstract class TextBoxBase extends AndroidViewComponent
       LostFocus();
     }
   }
+
+  @Override
+  public void setHighContrast(boolean isHighContrast) {
+    //background of button
+    if (backgroundColor == Component.COLOR_DEFAULT) {
+      if (isHighContrast) {
+        TextViewUtil.setBackgroundColor(view, Component.COLOR_BLACK);
+      }
+      else {
+        ViewUtil.setBackgroundDrawable(view, defaultTextBoxDrawable);
+      }
+    }
+
+    //color of text
+    if (textColor == Component.COLOR_DEFAULT) {
+      if (isHighContrast) {
+        TextViewUtil.setTextColor(view, COLOR_WHITE);
+        view.setHintTextColor(COLOR_YELLOW);
+
+      }
+      else {
+        TextViewUtil.setTextColor(view, container.$form().isDarkTheme() ? COLOR_WHITE : Component.COLOR_BLACK);
+        view.setHintTextColor(hintColorDefault);
+
+      }
+    }
+  }
+
+  @Override
+  public boolean getHighContrast() {
+    return isHighContrast;
+  }
+
+  @Override
+  public void setLargeFont(boolean isLargeFont) {
+    if (TextViewUtil.getFontSize(view, container.$context()) == 24.0 || TextViewUtil.getFontSize(view, container.$context()) == Component.FONT_DEFAULT_SIZE) {
+      if (isLargeFont) {
+        TextViewUtil.setFontSize(view, 24);
+      } else {
+        TextViewUtil.setFontSize(view, Component.FONT_DEFAULT_SIZE);
+      }
+    }
+  }
+
+  @Override
+  public boolean getLargeFont() {
+    return isBigText;
+  }
 }

appinventor/components/src/com/google/appinventor/components/runtime/ToggleBase.java

@@ -27,7 +27,7 @@ import android.widget.CompoundButton.OnCheckedChangeListener;
  */
 @SimpleObject
 public abstract class ToggleBase<T extends CompoundButton> extends AndroidViewComponent
-        implements OnCheckedChangeListener, OnFocusChangeListener {
+        implements OnCheckedChangeListener, OnFocusChangeListener, AccessibleComponent {
 
   protected T view;
 
@@ -46,6 +46,9 @@ public abstract class ToggleBase<T extends CompoundButton> extends AndroidViewCo
   // Backing for text color
   private int textColor;
 
+  // Whether the text is big or not
+  private boolean isBigText = false;
+
   /**
    * Creates a new ToggleBase component.
    *
@@ -79,6 +82,33 @@ public abstract class ToggleBase<T extends CompoundButton> extends AndroidViewCo
     return view;
   }
 
+
+  @Override
+  public void setHighContrast(boolean isHighContrast) {
+
+  }
+
+  @Override
+  public boolean getHighContrast() {
+    return false;
+  }
+
+  @Override
+  public void setLargeFont(boolean isLargeFont) {
+    if (TextViewUtil.getFontSize(view, container.$context()) == 24.0 || TextViewUtil.getFontSize(view, container.$context()) == Component.FONT_DEFAULT_SIZE) {
+      if (isLargeFont) {
+        TextViewUtil.setFontSize(view, 24);
+      } else {
+        TextViewUtil.setFontSize(view, Component.FONT_DEFAULT_SIZE);
+      }
+    }
+  }
+
+  @Override
+  public boolean getLargeFont() {
+    return isBigText;
+  }
+
   /**
    * User tapped and released the `%type%`.
    */
@@ -231,7 +261,17 @@ public abstract class ToggleBase<T extends CompoundButton> extends AndroidViewCo
   @SimpleProperty(description = "Specifies the text font size of the %type% in scale-independent "
       + "pixels.")
   public void FontSize(float size) {
-    TextViewUtil.setFontSize(view, size);
+    if (Math.abs(size-Component.FONT_DEFAULT_SIZE)<.01 || Math.abs(size-24)<.01) {
+      if (isBigText || container.$form().BigDefaultText()) {
+        TextViewUtil.setFontSize(view, 24);
+      }
+      else {
+        TextViewUtil.setFontSize(view, Component.FONT_DEFAULT_SIZE);
+      }
+    }
+    else {
+      TextViewUtil.setFontSize(view, size);
+    }
   }
 
   /**

appinventor/docs/html/reference/components/userinterface.html

@@ -410,6 +410,8 @@ Valid values for the month field are 1-12 and 1-31 for the day field.</dd>
 <h3 id="Image-Properties">Properties</h3>
 
 <dl class="properties">
+  <dt id="Image.AlternateText" class="text wo"><em>AlternateText</em></dt>
+  <dd>A written description of what the image looks like.</dd>
   <dt id="Image.Animation" class="text wo bo"><em>Animation</em></dt>
   <dd>This is a limited form of animation that can attach a small number of motion types to images.
  The allowable motions are <code class="highlighter-rouge">ScrollRightSlow</code>, <code class="highlighter-rouge">ScrollRight</code>, <code class="highlighter-rouge">ScrollRightFast</code>,
@@ -887,6 +889,8 @@ Valid values for the month field are 1-12 and 1-31 for the day field.</dd>
   <dt id="Screen.BackgroundImage" class="text"><em>BackgroundImage</em></dt>
   <dd>Specifies the path of the <code class="highlighter-rouge">Screen</code>’s background image. If there is both an <code class="highlighter-rouge">BackgroundImage</code>
  and a <a href="#Screen.BackgroundColor"><code class="highlighter-rouge">BackgroundColor</code></a> specified, only the <code class="highlighter-rouge">BackgroundImage</code> will be visible.</dd>
+  <dt id="Screen.BigDefaultText" class="boolean"><em>BigDefaultText</em></dt>
+  <dd>When checked, all default size text will be increased in size.</dd>
   <dt id="Screen.BlocksToolkit" class="text wo do"><em>BlocksToolkit</em></dt>
   <dd>A JSON string representing the subset for the screen. Authors of template apps can use this to control what components, designer properties, and blocks are available in the project.</dd>
   <dt id="Screen.CloseScreenAnimation" class="text"><em>CloseScreenAnimation</em></dt>
@@ -894,6 +898,8 @@ Valid values for the month field are 1-12 and 1-31 for the day field.</dd>
  to a form behind it in the activity stack.</dd>
   <dt id="Screen.Height" class="number ro bo"><em>Height</em></dt>
   <dd>Returns the Screen height in pixels (y-size).</dd>
+  <dt id="Screen.HighContrast" class="boolean"><em>HighContrast</em></dt>
+  <dd>When checked, there will be high contrast mode turned on.</dd>
   <dt id="Screen.Icon" class="text wo do"><em>Icon</em></dt>
   <dd>The image used for your App’s display icon should be a square png or jpeg image with dimensions
  up to 1024x1024 pixels. Larger images may cause compiling or installing the app to fail.

appinventor/docs/markdown/reference/components/userinterface.md

@@ -362,6 +362,9 @@ Component for displaying images and basic animations.
 
 {:.properties}
 
+{:id="Image.AlternateText" .text .wo} *AlternateText*
+: A written description of what the image looks like.
+
 {:id="Image.Animation" .text .wo .bo} *Animation*
 : This is a limited form of animation that can attach a small number of motion types to images.
  The allowable motions are `ScrollRightSlow`, `ScrollRight`, `ScrollRightFast`,
@@ -963,6 +966,9 @@ Top-level component containing all other components in the program.
 : Specifies the path of the `Screen`'s background image. If there is both an `BackgroundImage`
  and a [`BackgroundColor`](#Screen.BackgroundColor) specified, only the `BackgroundImage` will be visible.
 
+{:id="Screen.BigDefaultText" .boolean} *BigDefaultText*
+: When checked, all default size text will be increased in size.
+
 {:id="Screen.BlocksToolkit" .text .wo .do} *BlocksToolkit*
 : A JSON string representing the subset for the screen. Authors of template apps can use this to control what components, designer properties, and blocks are available in the project.
 
@@ -973,6 +979,9 @@ Top-level component containing all other components in the program.
 {:id="Screen.Height" .number .ro .bo} *Height*
 : Returns the Screen height in pixels (y-size).
 
+{:id="Screen.HighContrast" .boolean} *HighContrast*
+: When checked, there will be high contrast mode turned on.
+
 {:id="Screen.Icon" .text .wo .do} *Icon*
 : The image used for your App's display icon should be a square png or jpeg image with dimensions
  up to 1024x1024 pixels. Larger images may cause compiling or installing the app to fail.