Fix multiselect issue when changing tabs/windows (#2108)

* Fix multiselect issue when changing tabs/windows

Change-Id: Ic015672436e5a1b25d022eacc14998081b4b195b

appinventor/appengine/src/com/google/appinventor/client/boxes/BlockSelectorBox.java

@@ -13,6 +13,7 @@ import com.google.appinventor.client.output.OdeLog;
 import com.google.appinventor.client.widgets.boxes.Box;
 import com.google.appinventor.shared.settings.SettingsConstants;
 import com.google.common.collect.Maps;
+import com.google.gwt.dom.client.NativeEvent;
 import com.google.gwt.json.client.JSONObject;
 import com.google.gwt.json.client.JSONParser;
 import com.google.gwt.resources.client.ImageResource;
@@ -46,7 +47,7 @@ public final class BlockSelectorBox extends Box {
     }
 
     @Override
-    public void onSelected() {
+    public void onSelected(NativeEvent source) {
     }
 
     @Override
@@ -167,7 +168,7 @@ public final class BlockSelectorBox extends Box {
           + getBuiltinDrawerNames(drawerName) + "</span>"));
       SourceStructureExplorerItem sourceItem = new BlockSelectorItem() {
         @Override
-        public void onSelected() {
+        public void onSelected(NativeEvent source) {
           fireBuiltinDrawerSelected(drawerName);
         }
       };
@@ -230,7 +231,7 @@ public final class BlockSelectorBox extends Box {
           + ComponentsTranslation.getComponentName(typeName) + "</span>"));
       SourceStructureExplorerItem sourceItem = new BlockSelectorItem() {
         @Override
-        public void onSelected() {
+        public void onSelected(NativeEvent source) {
           fireGenericDrawerSelected(typeName);
         }
       };

appinventor/appengine/src/com/google/appinventor/client/editor/simple/SimpleNonVisibleComponentsPanel.java

@@ -126,7 +126,7 @@ public final class SimpleNonVisibleComponentsPanel extends Composite implements
 
     // Add component to this panel
     addComponent(sourceComponent);
-    sourceComponent.select();
+    sourceComponent.select(null);
   }
 
   @Override

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

@@ -198,7 +198,7 @@ public class MockCircle extends MockMapFeatureBaseWithFill {
     if (!circle.clickHandler) {
       while (el.lastChild) el.removeChild(el.lastChild);  // clear the div
       circle.clickHandler = function(e) {
-        this.@com.google.appinventor.client.editor.simple.components.MockCircle::select()();
+        this.@com.google.appinventor.client.editor.simple.components.MockCircle::select(*)(e);
         if (e.originalEvent) e.originalEvent.stopPropagation();
       };
       circle.dragHandler = function(e) {

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

@@ -12,7 +12,6 @@ import com.google.appinventor.client.editor.simple.SimpleComponentDatabase;
 import com.google.appinventor.client.ComponentsTranslation;
 import com.google.appinventor.client.Images;
 import com.google.appinventor.client.Ode;
-import com.google.appinventor.client.editor.ProjectEditor;
 import com.google.appinventor.client.editor.simple.SimpleEditor;
 import com.google.appinventor.client.editor.simple.components.utils.PropertiesUtil;
 import com.google.appinventor.client.editor.youngandroid.YaBlocksEditor;
@@ -35,8 +34,8 @@ import com.google.appinventor.shared.rpc.project.HasAssetsFolder;
 import com.google.appinventor.shared.rpc.project.ProjectNode;
 import com.google.appinventor.shared.rpc.project.youngandroid.YoungAndroidAssetsFolder;
 import com.google.appinventor.shared.rpc.project.youngandroid.YoungAndroidProjectNode;
-import com.google.appinventor.shared.settings.SettingsConstants;
 import com.google.appinventor.shared.storage.StorageUtil;
+import com.google.gwt.dom.client.NativeEvent;
 import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.event.dom.client.DomEvent;
@@ -79,7 +78,6 @@ import com.google.appinventor.shared.simple.ComponentDatabaseInterface.Component
 import com.google.appinventor.shared.simple.ComponentDatabaseInterface.PropertyDefinition;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -328,7 +326,7 @@ public abstract class MockComponent extends Composite implements PropertyChangeL
 
     sourceStructureExplorerItem = new SourceStructureExplorerItem() {
       @Override
-      public void onSelected() {
+      public void onSelected(NativeEvent source) {
         // are we showing the blocks editor? if so, toggle the component drawer
         if (Ode.getInstance().getCurrentFileEditor() instanceof YaBlocksEditor) {
           YaBlocksEditor blocksEditor =
@@ -336,7 +334,7 @@ public abstract class MockComponent extends Composite implements PropertyChangeL
           OdeLog.log("Showing item " + getName());
           blocksEditor.showComponentBlocks(getName());
         } else {
-          select();
+          select(source);
         }
       }
 
@@ -523,7 +521,33 @@ public abstract class MockComponent extends Composite implements PropertyChangeL
     if (isPropertyforYail(name)) {
       type |= EditableProperty.TYPE_DOYAIL;
     }
-    properties.addProperty(name, defaultValue, caption, editor, type);
+    properties.addProperty(name, defaultValue, caption, editor, type, "", null);
+  }
+
+  /**
+   * Adds a new property for the component.
+   *
+   * @param name  property name
+   * @param defaultValue  default value of property
+   * @param caption  property's caption for use in the ui
+   * @param editorType  editor type for the property
+   * @param editorArgs  additional editor arguments
+   * @param editor  property editor
+   */
+  public final void addProperty(String name, String defaultValue, String caption,
+      String editorType, String[] editorArgs, PropertyEditor editor) {
+
+    int type = EditableProperty.TYPE_NORMAL;
+    if (!isPropertyPersisted(name)) {
+      type |= EditableProperty.TYPE_NONPERSISTED;
+    }
+    if (!isPropertyVisible(name)) {
+      type |= EditableProperty.TYPE_INVISIBLE;
+    }
+    if (isPropertyforYail(name)) {
+      type |= EditableProperty.TYPE_DOYAIL;
+    }
+    properties.addProperty(name, defaultValue, caption, editor, type, editorType, editorArgs);
   }
 
   /**
@@ -655,8 +679,8 @@ public abstract class MockComponent extends Composite implements PropertyChangeL
   /**
    * Selects this component in the visual editor.
    */
-  public final void select() {
-    getForm().setSelectedComponent(this);
+  public final void select(NativeEvent event) {
+    getForm().setSelectedComponent(this, event);
   }
 
   /**
@@ -680,7 +704,7 @@ public abstract class MockComponent extends Composite implements PropertyChangeL
    * Returns whether this component is selected.
    */
   public boolean isSelected() {
-    return (getForm().getSelectedComponent() == this);
+    return (getForm().getSelectedComponents() == this);
   }
 
   /**
@@ -868,7 +892,7 @@ public abstract class MockComponent extends Composite implements PropertyChangeL
       case Event.ONTOUCHSTART:
       case Event.ONTOUCHEND:
         if (isForm()) {
-          select();
+          select(event);
         }
       case Event.ONTOUCHMOVE:
       case Event.ONTOUCHCANCEL:
@@ -887,7 +911,7 @@ public abstract class MockComponent extends Composite implements PropertyChangeL
 
       case Event.ONCLICK:
         cancelBrowserEvent(event);
-        select();
+        select(event);
         break;
 
       default:
@@ -1095,7 +1119,7 @@ public abstract class MockComponent extends Composite implements PropertyChangeL
 
   public void delete() {
     this.editor.getProjectEditor().clearLocation(getName());
-    getForm().select();
+    getForm().select(null);
     // Pass true to indicate that the component is being permanently deleted.
     getContainer().removeComponent(this, true);
     // tell the component its been removed, so it can remove children's blocks
@@ -1183,7 +1207,7 @@ public abstract class MockComponent extends Composite implements PropertyChangeL
     for (PropertyDefinition property : newProperties) {
       if (toBeAdded.contains(property.getName())) {
         PropertyEditor propertyEditor = PropertiesUtil.createPropertyEditor(property.getEditorType(), property.getDefaultValue(), (YaFormEditor) editor, property.getEditorArgs());
-        addProperty(property.getName(), property.getDefaultValue(), property.getCaption(), propertyEditor);
+        addProperty(property.getName(), property.getDefaultValue(), property.getCaption(), property.getEditorType(), property.getEditorArgs(), propertyEditor);
       }
     }
 

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

@@ -300,7 +300,7 @@ public abstract class MockContainer extends MockVisibleComponent implements Drop
     }
 
     if (layout.onDrop(sourceComponent, x, y, offsetX, offsetY)) {
-      sourceComponent.select();
+      sourceComponent.select(null);
     }
   }
 

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

@@ -8,6 +8,8 @@ package com.google.appinventor.client.editor.simple.components;
 
 import static com.google.appinventor.client.Ode.MESSAGES;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -22,14 +24,17 @@ import com.google.appinventor.client.output.OdeLog;
 import com.google.appinventor.client.properties.BadPropertyEditorException;
 import com.google.appinventor.client.widgets.properties.EditableProperties;
 import com.google.appinventor.components.common.ComponentConstants;
+import com.google.appinventor.components.common.PropertyTypeConstants;
 import com.google.appinventor.shared.settings.SettingsConstants;
 import com.google.gwt.dom.client.DivElement;
 import com.google.gwt.dom.client.Document;
 import com.google.gwt.dom.client.Element;
+import com.google.gwt.dom.client.NativeEvent;
 import com.google.gwt.dom.client.Style;
 
 import com.google.gwt.user.client.Timer;
 
+import com.google.gwt.user.client.Window;
 import com.google.gwt.user.client.ui.AbsolutePanel;
 import com.google.gwt.user.client.ui.Button;
 import com.google.gwt.user.client.ui.Composite;
@@ -232,7 +237,7 @@ public final class MockForm extends MockContainer {
   ScrollPanel scrollPanel;
   private TitleBar titleBar;
   private NavigationBar navigationBar;
-  private MockComponent selectedComponent;
+  private List<MockComponent> selectedComponents = new ArrayList<MockComponent>(Collections.singleton(this));
 
   int screenWidth;              // TEMP: Make package visible so we can use it MockHVLayoutBase
   private int screenHeight;
@@ -450,8 +455,10 @@ public final class MockForm extends MockContainer {
   @Override
   protected void addWidthHeightProperties() {
     addProperty(PROPERTY_NAME_WIDTH, "" + PORTRAIT_WIDTH, null,
+        PropertyTypeConstants.PROPERTY_TYPE_LENGTH, null,
         new YoungAndroidLengthPropertyEditor());
     addProperty(PROPERTY_NAME_HEIGHT, "" + LENGTH_PREFERRED, null,
+        PropertyTypeConstants.PROPERTY_TYPE_LENGTH, null,
         new YoungAndroidLengthPropertyEditor());
   }
 
@@ -904,48 +911,61 @@ public final class MockForm extends MockContainer {
     }
   }
 
+  private boolean shouldSelectMultipleComponents(NativeEvent e) {
+    if (e == null) {
+      return false;
+    }
+    if (Window.Navigator.getPlatform().toLowerCase().startsWith("mac")) {
+      return e.getMetaKey();
+    } else {
+      return e.getCtrlKey();
+    }
+  }
+
   /**
    * Changes the component that is currently selected in the form.
    * <p>
    * There will always be exactly one component selected in a form
    * at any given time.
    */
-  public final void setSelectedComponent(MockComponent newSelectedComponent) {
-    MockComponent oldSelectedComponent = selectedComponent;
-
+  public final void setSelectedComponent(MockComponent newSelectedComponent, NativeEvent event) {
     if (newSelectedComponent == null) {
       throw new IllegalArgumentException("at least one component must always be selected");
     }
-    YaFormEditor formEditor = (YaFormEditor) editor;
-    boolean shouldSelectMultipleComponents = formEditor.getShouldSelectMultipleComponents();
-    List<MockComponent> selectedComponents = formEditor.getSelectedComponents();
+    boolean shouldSelectMultipleComponents = shouldSelectMultipleComponents(event);
     if (selectedComponents.size() == 1 && selectedComponents.contains(newSelectedComponent)) {
       // Attempting to change the selection from old to new when they are the same breaks
       // Marker drag. See https://github.com/mit-cml/appinventor-sources/issues/1936
       return;
     }
-    if (shouldSelectMultipleComponents && selectedComponents.size() > 1 && formEditor.isSelectedComponent(newSelectedComponent)) {
-      int index = selectedComponents.indexOf(newSelectedComponent);
-      selectedComponent = selectedComponents.get((index == 0) ? 1 : index - 1);
+
+    // Remove an previously selected component from the list of selected components, but only if
+    // there would still be something selected.
+    if (shouldSelectMultipleComponents && selectedComponents.contains(newSelectedComponent)
+        && selectedComponents.size() > 1) {
+      selectedComponents.remove(newSelectedComponent);
       newSelectedComponent.onSelectedChange(false);
       return;
     }
 
-    selectedComponent = newSelectedComponent;
-    Map<String, MockComponent> componentsMap = formEditor.getComponents();
-
-    if (oldSelectedComponent != null && !shouldSelectMultipleComponents) {     // Can be null initially
-      for (MockComponent component : componentsMap.values()) {
-        if (component.getName() != selectedComponent.getName()) {
+    if (!shouldSelectMultipleComponents) {
+      for (MockComponent component : selectedComponents) {
+        if (component != newSelectedComponent) {
           component.onSelectedChange(false);
         }
       }
+      selectedComponents.clear();
     }
+    selectedComponents.add(newSelectedComponent);
     newSelectedComponent.onSelectedChange(true);
   }
 
-  public final MockComponent getSelectedComponent() {
-    return selectedComponent;
+  public final List<MockComponent> getSelectedComponents() {
+    return selectedComponents;
+  }
+
+  public final MockComponent getLastSelectedComponent() {
+    return selectedComponents.get(selectedComponents.size() - 1);
   }
 
   /**

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

@@ -118,7 +118,7 @@ public class MockLineString extends MockMapFeatureBase {
     if (!polyline.clickHandler) {
       while (el.lastChild) el.removeChild(el.lastChild);  // clear the div
       polyline.clickHandler = function(e) {
-        this.@com.google.appinventor.client.editor.simple.components.MockLineString::select()();
+        this.@com.google.appinventor.client.editor.simple.components.MockLineString::select(*)(e);
         if (e.originalEvent) e.originalEvent.stopPropagation();
       };
       polyline.dragHandler = function() {

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

@@ -538,7 +538,7 @@ public final class MockMap extends MockContainer {
             // This is not desirable because it causes issues with the selected component.
             return;
           } else if (el === background) {
-            this.owner.@com.google.appinventor.client.editor.simple.components.MockComponent::select()();
+            this.owner.@com.google.appinventor.client.editor.simple.components.MockComponent::select(*)(e);
             return;
           }
           el = el.parentNode;

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

@@ -420,7 +420,7 @@ public class MockMarker extends MockMapFeatureBaseWithFill {
     map.addLayer(marker);
     if (!marker.clickHandler) {
       marker.clickHandler = function(e) {
-        self.@com.google.appinventor.client.editor.simple.components.MockMarker::select()();
+        self.@com.google.appinventor.client.editor.simple.components.MockMarker::select(*)(e);
         if (e.originalEvent) e.originalEvent.stopPropagation();
       };
       marker.dragHandler = function(e) {

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

@@ -168,7 +168,7 @@ public class MockPolygon extends MockPolygonBase {
     if (!polygon.clickHandler) {
       while (el.lastChild) el.removeChild(el.lastChild);  // clear the div
       polygon.clickHandler = function(e) {
-        this.@com.google.appinventor.client.editor.simple.components.MockMapFeatureBase::select()();
+        this.@com.google.appinventor.client.editor.simple.components.MockMapFeatureBase::select(*)(e);
         if (e.originalEvent) {
           if ((e.originalEvent.metaKey || e.originalEvent.ctrlKey) && polygon.editEnabled()) {
             polygon.editor.newHole(e.latlng);

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

@@ -164,7 +164,7 @@ public class MockRectangle extends MockPolygonBase {
     if (!rect.clickHandler) {
       while (el.lastChild) el.removeChild(el.lastChild);  // clear the div
       rect.clickHandler = function (e) {
-        this.@com.google.appinventor.client.editor.simple.components.MockMapFeatureBase::select()();
+        this.@com.google.appinventor.client.editor.simple.components.MockMapFeatureBase::select(*)(e);
         if (e.originalEvent) e.originalEvent.stopPropagation();
       };
       rect.dragHandler = function () {

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

@@ -11,6 +11,7 @@ import com.google.appinventor.client.editor.simple.SimpleEditor;
 import com.google.appinventor.client.editor.youngandroid.properties.YoungAndroidLengthPropertyEditor;
 import com.google.appinventor.client.widgets.properties.TextPropertyEditor;
 import com.google.appinventor.components.common.ComponentConstants;
+import com.google.appinventor.components.common.PropertyTypeConstants;
 import com.google.gwt.resources.client.ImageResource;
 import com.google.gwt.user.client.ui.Image;
 import com.google.gwt.user.client.ui.Widget;
@@ -88,8 +89,10 @@ public abstract class MockVisibleComponent extends MockComponent {
 
   protected void addWidthHeightProperties() {
     addProperty(PROPERTY_NAME_WIDTH, "" + LENGTH_PREFERRED, MESSAGES.widthPropertyCaption(),
+        PropertyTypeConstants.PROPERTY_TYPE_LENGTH, null,
         new YoungAndroidLengthPropertyEditor());
     addProperty(PROPERTY_NAME_HEIGHT, "" + LENGTH_PREFERRED, MESSAGES.heightPropertyCaption(),
+        PropertyTypeConstants.PROPERTY_TYPE_LENGTH, null,
         new YoungAndroidLengthPropertyEditor());
   }
 

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

@@ -30,6 +30,7 @@ import com.google.appinventor.client.editor.youngandroid.properties.YoungAndroid
 import com.google.appinventor.client.editor.youngandroid.properties.YoungAndroidLegoEv3SensorPortChoicePropertyEditor;
 import com.google.appinventor.client.editor.youngandroid.properties.YoungAndroidLegoEv3UltrasonicSensorModeChoicePropertyEditor;
 import com.google.appinventor.client.editor.youngandroid.properties.YoungAndroidLegoNxtSensorPortChoicePropertyEditor;
+import com.google.appinventor.client.editor.youngandroid.properties.YoungAndroidLengthPropertyEditor;
 import com.google.appinventor.client.editor.youngandroid.properties.YoungAndroidMapScaleUnitsPropertyEditor;
 import com.google.appinventor.client.editor.youngandroid.properties.YoungAndroidMapTypePropertyEditor;
 import com.google.appinventor.client.editor.youngandroid.properties.YoungAndroidScreenAnimationChoicePropertyEditor;
@@ -98,6 +99,7 @@ public class PropertiesUtil {
     for (ComponentDatabaseInterface.PropertyDefinition property : propertyDefintions) {
       mockComponent.addProperty(property.getName(), property.getDefaultValue(),
           ComponentsTranslation.getPropertyName(property.getCaption()),
+          property.getEditorType(), property.getEditorArgs(),
           PropertiesUtil.createPropertyEditor(property.getEditorType(), property.getDefaultValue(), editor, property.getEditorArgs()));
       /*OdeLog.log("Property Caption: " + property.getCaption() + ", "
           + TranslationComponentProperty.getName(property.getCaption()));*/
@@ -220,6 +222,8 @@ public class PropertiesUtil {
     } else if (editorType.equals(PropertyTypeConstants.PROPERTY_TYPE_LEGO_NXT_GENERATED_COLOR)) {
       return new YoungAndroidColorChoicePropertyEditor(
           YoungAndroidColorChoicePropertyEditor.NXT_GENERATED_COLORS, defaultValue);
+    } else if (editorType.equals(PropertyTypeConstants.PROPERTY_TYPE_LENGTH)) {
+      return new YoungAndroidLengthPropertyEditor();
     } else if (editorType.equals(PropertyTypeConstants.PROPERTY_TYPE_LONGITUDE)) {
       return new YoungAndroidFloatRangePropertyEditor(-180, 180);
     } else if (editorType.equals(PropertyTypeConstants.PROPERTY_TYPE_MAP_TYPE)) {

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

@@ -589,7 +589,7 @@ public final class YaBlocksEditor extends FileEditor
   private void updateSourceStructureExplorer() {
     MockForm form = getForm();
     if (form != null) {
-      updateBlocksTree(form, form.getSelectedComponent().getSourceStructureExplorerItem());
+      updateBlocksTree(form, form.getLastSelectedComponent().getSourceStructureExplorerItem());
     }
   }
 

appinventor/appengine/src/com/google/appinventor/client/explorer/SourceStructureExplorer.java

@@ -7,10 +7,10 @@
 package com.google.appinventor.client.explorer;
 
 import com.google.appinventor.client.Ode;
-import com.google.appinventor.client.output.OdeLog;
 import com.google.appinventor.client.widgets.TextButton;
 import com.google.gwt.event.dom.client.*;
 import com.google.gwt.event.logical.shared.*;
+import com.google.gwt.user.client.Event;
 import com.google.gwt.user.client.ui.*;
 
 import java.util.Iterator;
@@ -26,16 +26,38 @@ import static com.google.appinventor.client.Ode.MESSAGES;
  */
 public class SourceStructureExplorer extends Composite {
   // UI elements
-  private final Tree tree;
+  private final EventCaptureTree tree;
   private final TextButton renameButton;
   private final TextButton deleteButton;
 
+  /**
+   * This is a hack to work around the fact that for multiselect we need to have
+   * access to the state of the meta/ctrl key but the SelectionHandler doesn't
+   * provide access to the original event that caused the selection. We capture
+   * the most recent event before the selection event is triggered and then
+   * reset once the selection has been updated.
+   */
+  static class EventCaptureTree extends Tree {
+
+    Event lastEvent = null;
+
+    public EventCaptureTree(Resources resources) {
+      super(resources);
+    }
+
+    @Override
+    public void onBrowserEvent(Event event) {
+      lastEvent = event;
+      super.onBrowserEvent(event);
+    }
+  }
+
   /**
    * Creates a new source structure explorer.
    */
   public SourceStructureExplorer() {
     // Initialize UI elements
-    tree = new Tree(Ode.getImageBundle());
+    tree = new EventCaptureTree(Ode.getImageBundle());
     tree.setAnimationEnabled(true);
     tree.setScrollOnSelectEnabled(false);
     tree.addCloseHandler(new CloseHandler<TreeItem>() {
@@ -74,7 +96,7 @@ public class SourceStructureExplorer extends Composite {
             SourceStructureExplorerItem item = (SourceStructureExplorerItem) userObject;
             enableButtons(item);
             //showBlocks(item);
-            item.onSelected();
+            item.onSelected(tree.lastEvent);
           } else {
             disableButtons();
             //hideComponent();
@@ -82,6 +104,7 @@ public class SourceStructureExplorer extends Composite {
         } else {
           disableButtons();
         }
+        tree.lastEvent = null;
       }
     });
     tree.addKeyDownHandler(new KeyDownHandler() {

appinventor/appengine/src/com/google/appinventor/client/explorer/SourceStructureExplorerItem.java

@@ -6,6 +6,8 @@
 
 package com.google.appinventor.client.explorer;
 
+import com.google.gwt.dom.client.NativeEvent;
+
 /**
  * Defines an interface for an item in the source structure explorer.
  *
@@ -15,7 +17,7 @@ public interface SourceStructureExplorerItem {
   /**
    * Invoked when this item is selected.
    */
-  void onSelected();
+  void onSelected(NativeEvent source);
 
   /**
    * Invoked when this item is expanded or collapsed

appinventor/appengine/src/com/google/appinventor/client/widgets/dnd/DragSourceSupport.java

@@ -410,13 +410,13 @@ public final class DragSourceSupport implements MouseListener, TouchStartHandler
   }
 
   @Override
-  public void onTouchEnd(TouchEndEvent event) {
+  public void onTouchEnd(final TouchEndEvent event) {
     final Widget src = (Widget) event.getSource();
     if (src instanceof MockComponent) {  // We only select on CLICK, which isn't generated on mobile
       DeferredCommand.addCommand(new Command() {
         @Override
         public void execute() {
-          ((MockComponent) src).select();
+          ((MockComponent) src).select(event.getNativeEvent());
         }
       });
     }

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

@@ -50,8 +50,8 @@ public class EditableProperties extends Properties<EditableProperty> {
    */
 
   public void addProperty(String name, String defaultValue, String caption,
-      PropertyEditor editor, int type) {
-    addProperty(new EditableProperty(this, name, defaultValue, caption, editor, type));
+      PropertyEditor editor, int type, String editorType, String[] editorArgs) {
+    addProperty(new EditableProperty(this, name, defaultValue, caption, editor, type, editorType, editorArgs));
   }
 
   @Override

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

@@ -57,6 +57,12 @@ public final class EditableProperty extends Property {
   // Property caption for use in properties panel
   private final String caption;
 
+  // Editor type of the property (for creating new editors)
+  private final String editorType;
+
+  // Additional arguments for the editor
+  private final String[] editorArgs;
+
   /**
    * Creates a new property.
    *
@@ -70,17 +76,24 @@ public final class EditableProperty extends Property {
    * @param type  type of property; see {@code TYPE_*} constants
    */
   public EditableProperty(EditableProperties properties, String name, String defaultValue,
-      String caption, PropertyEditor editor, int type) {
+      String caption, PropertyEditor editor, int type, String editorType, String[] editorArgs) {
     super(name, defaultValue);
 
     this.properties = properties;
     this.type = type;
     this.editor = editor;
     this.caption = caption;
+    this.editorType = editorType;
+    this.editorArgs = editorArgs;
 
     editor.setProperty(this);
   }
 
+  public EditableProperty(EditableProperties properties, String name, String defaultValue,
+      int type) {
+    this(properties, name, defaultValue, name, new TextPropertyEditor(), type, "", null);
+  }
+
   /**
    * Creates a new property.
    *
@@ -92,8 +105,8 @@ public final class EditableProperty extends Property {
    * @param type  type of property; see {@code TYPE_*} constants
    */
   public EditableProperty(EditableProperties properties, String name, String defaultValue,
-      int type) {
-    this(properties, name, defaultValue, name, new TextPropertyEditor(), type);
+      int type, String editorType, String[] editorArgs) {
+    this(properties, name, defaultValue, name, new TextPropertyEditor(), type, editorType, editorArgs);
   }
 
   /**
@@ -150,6 +163,14 @@ public final class EditableProperty extends Property {
     return caption;
   }
 
+  public String getEditorType() {
+    return editorType;
+  }
+
+  public String[] getEditorArgs() {
+    return editorArgs;
+  }
+
 
   /**
    * Called when this property is being orphaned.

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

@@ -42,4 +42,8 @@ public abstract class PropertyEditor extends Composite {
    */
   public void orphan() {
   }
+
+  public void refresh() {
+    this.updateValue();
+  }
 }

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

@@ -156,6 +156,12 @@ public class PropertyTypeConstants {
    */
   public static final String PROPERTY_TYPE_CHOICES = "choices";
 
+  /**
+   * Length editor (e.g., width, height)
+   * @see com.google.appinventor.client.editor.youngandroid.properties.YoungAndroidLengthPropertyEditor
+   */
+  public static final String PROPERTY_TYPE_LENGTH = "length";
+
   /**
    * Floating-point values in the range of valid longitudes [-180, 180].
    * @see com.google.appinventor.client.editor.youngandroid.properties.YoungAndroidFloatRangePropertyEditor