Enable multiple component selection using shift key presses (#1891)

* Enable multiple component selection using shift key presses
* Add highlight to select components and show number of components selected
* Make selected component properties default when there is no full intersection
* Allow unselection of already selected components

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

@@ -10,6 +10,7 @@ import static com.google.appinventor.client.Ode.MESSAGES;
 
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 
 import com.google.appinventor.client.editor.simple.SimpleEditor;
@@ -915,14 +916,25 @@ public final class MockForm extends MockContainer {
     if (newSelectedComponent == null) {
       throw new IllegalArgumentException("at least one component must always be selected");
     }
-    if (newSelectedComponent == oldSelectedComponent) {
+    YaFormEditor formEditor = (YaFormEditor) editor;
+    boolean shouldSelectMultipleComponents = formEditor.getShouldSelectMultipleComponents();
+    List<MockComponent> selectedComponents = formEditor.getSelectedComponents();
+    if (shouldSelectMultipleComponents && selectedComponents.size() > 1 && formEditor.isSelectedComponent(newSelectedComponent)) {
+      int index = selectedComponents.indexOf(newSelectedComponent);
+      selectedComponent = selectedComponents.get((index == 0) ? 1 : index - 1);
+      newSelectedComponent.onSelectedChange(false);
       return;
     }
 
     selectedComponent = newSelectedComponent;
+    Map<String, MockComponent> componentsMap = formEditor.getComponents();
 
-    if (oldSelectedComponent != null) {     // Can be null initially
-      oldSelectedComponent.onSelectedChange(false);
+    if (oldSelectedComponent != null && !shouldSelectMultipleComponents) {     // Can be null initially
+      for (MockComponent component : componentsMap.values()) {
+        if (component.getName() != selectedComponent.getName()) {
+          component.onSelectedChange(false);
+        }
+      }
     }
     newSelectedComponent.onSelectedChange(true);
   }

appinventor/appengine/src/com/google/appinventor/client/editor/simple/palette/AbstractPaletteItemWidget.java

@@ -4,7 +4,6 @@
 // http://www.apache.org/licenses/LICENSE-2.0
 
 package com.google.appinventor.client.editor.simple.palette;
-
 import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.event.dom.client.TouchEndEvent;

appinventor/appengine/src/com/google/appinventor/client/editor/youngandroid/YaFormEditor.java

@@ -36,7 +36,9 @@ import com.google.appinventor.client.properties.json.ClientJsonParser;
 import com.google.appinventor.client.properties.json.ClientJsonString;
 import com.google.appinventor.client.widgets.dnd.DropTarget;
 import com.google.appinventor.client.widgets.properties.EditableProperties;
+import com.google.appinventor.client.widgets.properties.EditableProperty;
 import com.google.appinventor.client.widgets.properties.PropertiesPanel;
+import com.google.appinventor.client.widgets.properties.PropertyChangeListener;
 import com.google.appinventor.client.youngandroid.YoungAndroidFormUpgrader;
 import com.google.appinventor.components.common.YaVersion;
 import com.google.appinventor.shared.properties.json.JSONArray;
@@ -51,9 +53,15 @@ import com.google.appinventor.shared.youngandroid.YoungAndroidSourceAnalyzer;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Maps;
 import com.google.gwt.core.client.Callback;
+import com.google.gwt.event.dom.client.KeyCodes;
+import com.google.gwt.event.dom.client.KeyDownEvent;
+import com.google.gwt.event.dom.client.KeyDownHandler;
+import com.google.gwt.event.dom.client.KeyUpEvent;
+import com.google.gwt.event.dom.client.KeyUpHandler;
 import com.google.gwt.user.client.Command;
 import com.google.gwt.user.client.Window;
 import com.google.gwt.user.client.ui.DockPanel;
+import com.google.gwt.user.client.ui.RootPanel;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -72,7 +80,7 @@ import java.util.Set;
  * @author markf@google.com (Mark Friedman)
  * @author lizlooney@google.com (Liz Looney)
  */
-public final class YaFormEditor extends SimpleEditor implements FormChangeListener, ComponentDatabaseChangeListener {
+public final class YaFormEditor extends SimpleEditor implements FormChangeListener, ComponentDatabaseChangeListener, PropertyChangeListener {
 
   private static class FileContentHolder {
     private String content;
@@ -136,6 +144,10 @@ public final class YaFormEditor extends SimpleEditor implements FormChangeListen
 
   private static final int OLD_PROJECT_YAV = 150; // Projects older then this have no authURL
 
+  private boolean shouldSelectMultipleComponents = false;
+  private EditableProperties selectedProperties = null;
+  private List<MockComponent> selectedComponents = new ArrayList<MockComponent>();
+
   /**
    * Creates a new YaFormEditor.
    *
@@ -162,6 +174,24 @@ public final class YaFormEditor extends SimpleEditor implements FormChangeListen
     componentsPanel.add(visibleComponentsPanel, DockPanel.NORTH);
     componentsPanel.add(nonVisibleComponentsPanel, DockPanel.SOUTH);
     componentsPanel.setSize("100%", "100%");
+    RootPanel.get().addDomHandler(new KeyDownHandler() {
+      @Override
+      public void onKeyDown(KeyDownEvent event) {
+        int keyCode = event.getNativeKeyCode();
+        if (keyCode == KeyCodes.KEY_SHIFT) {
+          shouldSelectMultipleComponents = true;
+        }
+      }
+    }, KeyDownEvent.getType());
+    RootPanel.get().addDomHandler(new KeyUpHandler() {
+      @Override
+      public void onKeyUp(KeyUpEvent event) {
+        int keyCode = event.getNativeKeyCode();
+        if (keyCode == KeyCodes.KEY_SHIFT) {
+          shouldSelectMultipleComponents = false;
+        }
+      }
+    }, KeyUpEvent.getType());
 
     // Create palettePanel, which will be used as the content of the PaletteBox.
     palettePanel = new YoungAndroidPalettePanel(this);
@@ -187,6 +217,14 @@ public final class YaFormEditor extends SimpleEditor implements FormChangeListen
     setSize("100%", "100%");
   }
 
+  public List<MockComponent> getSelectedComponents() {
+    return selectedComponents;
+  }
+
+  public boolean getShouldSelectMultipleComponents() {
+    return shouldSelectMultipleComponents;
+  }
+  
   public boolean shouldDisplayHiddenComponents() {
     return visibleComponentsPanel.isHiddenComponentsCheckboxChecked();
   }
@@ -319,6 +357,15 @@ public final class YaFormEditor extends SimpleEditor implements FormChangeListen
     return formNode.isScreen1();
   }
 
+  // PropertyChangeListener implementation
+
+  @Override
+  public void onPropertyChange(String propertyName, String propertyValue) {
+    for (MockComponent selectedComponent : selectedComponents) {
+      selectedComponent.changeProperty(propertyName, propertyValue);
+    }
+  }
+
   // FormChangeListener implementation
 
   @Override
@@ -335,10 +382,42 @@ public final class YaFormEditor extends SimpleEditor implements FormChangeListen
     }
   }
 
+  private boolean isIntersectedProperty(String propertyName) {
+    for (MockComponent selectedComponent : selectedComponents) {
+      if (!selectedComponent.hasProperty(propertyName)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
   @Override
   public void onComponentRemoved(MockComponent component, boolean permanentlyDeleted) {
     if (loadComplete) {
       if (permanentlyDeleted) {
+        if (isSelectedComponent(component)) {
+          selectedComponents.remove(component);
+          EditableProperties propertyIntersection = new EditableProperties(true);
+          for (MockComponent selectedComponent : selectedComponents) {
+            for (EditableProperty property : selectedComponent.getProperties()) {
+              String propertyName = property.getName();
+              if (propertyName == "Uuid") {
+                continue;
+              }
+              if (isIntersectedProperty(propertyName)) {
+                propertyIntersection.addProperty(
+                  propertyName, 
+                  property.getDefaultValue(),
+                  property.getCaption(), 
+                  property.getEditor(), 
+                  property.getType()
+                );
+              }
+            }
+          }
+          selectedProperties = propertyIntersection;
+          selectedProperties.addPropertyChangeListener(this);
+        }
         onFormStructureChange();
       }
     } else {
@@ -349,6 +428,8 @@ public final class YaFormEditor extends SimpleEditor implements FormChangeListen
   @Override
   public void onComponentAdded(MockComponent component) {
     if (loadComplete) {
+      selectedProperties = component.getProperties();
+      selectedComponents = new ArrayList<MockComponent>();
       onFormStructureChange();
     } else {
       OdeLog.elog("onComponentAdded called when loadComplete is false");
@@ -365,18 +446,87 @@ public final class YaFormEditor extends SimpleEditor implements FormChangeListen
     }
   }
 
+  public boolean isSelectedComponent(MockComponent component) {
+    String name = component.getName();
+    for (MockComponent selectedComponent : selectedComponents) {
+      if (selectedComponent.getName() == name) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  private boolean isIntersectedValue(String propertyName) {
+    String value = null;
+    for (MockComponent selectedComponent : selectedComponents) {
+      String propertyValue = selectedComponent.getPropertyValue(propertyName);
+      if (value == null) {
+        value = propertyValue;
+      } else if (!value.equals(propertyValue)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
   @Override
   public void onComponentSelectionChange(MockComponent component, boolean selected) {
     if (loadComplete) {
       if (selected) {
         // Select the item in the source structure explorer.
         sourceStructureExplorer.selectItem(component.getSourceStructureExplorerItem());
-
+        EditableProperties componentProperties = component.getProperties();
+        if (selectedProperties != null && shouldSelectMultipleComponents) {
+          if (!isSelectedComponent(component)) {
+            selectedComponents.add(component);
+          }
+          EditableProperties propertyIntersection = new EditableProperties(true);
+          for (EditableProperty property : componentProperties) {
+            String propertyName = property.getName();
+            if (propertyName == "Uuid") {
+              continue;
+            }
+            if (selectedProperties.hasProperty(propertyName)) {
+              propertyIntersection.addProperty(
+                propertyName, 
+                (isIntersectedValue(propertyName)) ? property.getValue() : property.getDefaultValue(),
+                property.getCaption(), 
+                property.getEditor(), 
+                property.getType()
+              );
+            }
+          }
+          selectedProperties = propertyIntersection;
+          selectedProperties.addPropertyChangeListener(this);
+        } else {
+          selectedComponents = new ArrayList<MockComponent>();
+          selectedComponents.add(component);
+          selectedProperties = componentProperties;
+        }
         // Show the component properties in the properties panel.
         updatePropertiesPanel(component);
-      } else {
-        // Unselect the item in the source structure explorer.
-        sourceStructureExplorer.unselectItem(component.getSourceStructureExplorerItem());
+      } else if (isSelectedComponent(component) && selectedComponents.size() > 1) {
+        selectedComponents.remove(component);
+        EditableProperties propertyIntersection = new EditableProperties(true);
+        for (EditableProperty property : selectedComponents.get(0).getProperties()) {
+          String propertyName = property.getName();
+          if (propertyName == "Uuid") {
+            continue;
+          }
+          if (isIntersectedProperty(propertyName)) {
+            propertyIntersection.addProperty(
+              propertyName, 
+              (isIntersectedValue(propertyName)) ? property.getValue() : property.getDefaultValue(),
+              property.getCaption(), 
+              property.getEditor(), 
+              property.getType()
+            );
+          }
+        }
+        selectedProperties = propertyIntersection;
+        selectedProperties.addPropertyChangeListener(this);
+        updatePropertiesPanel(selectedComponents.size() == 1 ? selectedComponents.get(0) : null);
+        onFormStructureChange();
       }
     } else {
       OdeLog.elog("onComponentSelectionChange called when loadComplete is false");
@@ -701,10 +851,15 @@ public final class YaFormEditor extends SimpleEditor implements FormChangeListen
    * Show the given component's properties in the properties panel.
    */
   private void updatePropertiesPanel(MockComponent component) {
-    designProperties.setProperties(component.getProperties());
-    // need to update the caption after the setProperties call, since
-    // setProperties clears the caption!
-    designProperties.setPropertiesCaption(component.getName());
+    if (selectedComponents.size() > 1) {
+      designProperties.setProperties(selectedProperties);
+      designProperties.setPropertiesCaption(selectedComponents.size() + " components selected");
+    } else {
+      designProperties.setProperties(component.getProperties());
+      // need to update the caption after the setProperties call, since
+      // setProperties clears the caption!
+      designProperties.setPropertiesCaption(component.getName());
+    }
   }
 
   private void onFormStructureChange() {

appinventor/appengine/src/com/google/appinventor/client/widgets/properties/EditableProperty.java

@@ -146,7 +146,7 @@ public final class EditableProperty extends Property {
    *
    * @return  property caption
    */
-  String getCaption() {
+  public String getCaption() {
     return caption;
   }