Generalize support for 'App Info', 'Uninstall' and 'Delete'

This allows other DragSource's to allow this behaviour, instead of it being
tied to specific source types.

Change-Id: I06b7c39b1b34a0ae141245bcc13b6a0873a4c0fd
diff --git a/src/com/android/launcher3/AppsCustomizePagedView.java b/src/com/android/launcher3/AppsCustomizePagedView.java
index 688ff82..2865bc5 100644
--- a/src/com/android/launcher3/AppsCustomizePagedView.java
+++ b/src/com/android/launcher3/AppsCustomizePagedView.java
@@ -916,6 +916,16 @@
     }
 
     @Override
+    public boolean supportsAppInfoDropTarget() {
+        return true;
+    }
+
+    @Override
+    public boolean supportsDeleteDropTarget() {
+        return false;
+    }
+
+    @Override
     public float getIntrinsicIconScaleFactor() {
         LauncherAppState app = LauncherAppState.getInstance();
         DeviceProfile grid = app.getDynamicGrid().getDeviceProfile();
diff --git a/src/com/android/launcher3/DeleteDropTarget.java b/src/com/android/launcher3/DeleteDropTarget.java
index 4023daf..7e0e5eb 100644
--- a/src/com/android/launcher3/DeleteDropTarget.java
+++ b/src/com/android/launcher3/DeleteDropTarget.java
@@ -95,7 +95,7 @@
     }
 
     private boolean isAllAppsApplication(DragSource source, Object info) {
-        return (source instanceof AppsCustomizePagedView) && (info instanceof AppInfo);
+        return source.supportsAppInfoDropTarget() && (info instanceof AppInfo);
     }
     private boolean isAllAppsWidget(DragSource source, Object info) {
         if (source instanceof AppsCustomizePagedView) {
@@ -175,6 +175,7 @@
         boolean isVisible = true;
         boolean useUninstallLabel = !AppsCustomizePagedView.DISABLE_ALL_APPS &&
                 isAllAppsApplication(source, info);
+        boolean useDeleteLabel = !useUninstallLabel && source.supportsDeleteDropTarget();
 
         // If we are dragging an application from AppsCustomize, only show the control if we can
         // delete the app (it was downloaded), and rename the string to "uninstall" in such a case.
@@ -185,15 +186,17 @@
 
         if (useUninstallLabel) {
             setCompoundDrawablesRelativeWithIntrinsicBounds(mUninstallDrawable, null, null, null);
-        } else {
+        } else if (useDeleteLabel) {
             setCompoundDrawablesRelativeWithIntrinsicBounds(mRemoveDrawable, null, null, null);
+        } else {
+            isVisible = false;
         }
         mCurrentDrawable = (TransitionDrawable) getCurrentDrawable();
 
         mActive = isVisible;
         resetHoverColor();
         ((ViewGroup) getParent()).setVisibility(isVisible ? View.VISIBLE : View.GONE);
-        if (getText().length() > 0) {
+        if (isVisible && getText().length() > 0) {
             setText(useUninstallLabel ? R.string.delete_target_uninstall_label
                 : R.string.delete_target_label);
         }
diff --git a/src/com/android/launcher3/DragSource.java b/src/com/android/launcher3/DragSource.java
index cca9ab1..7369eea 100644
--- a/src/com/android/launcher3/DragSource.java
+++ b/src/com/android/launcher3/DragSource.java
@@ -30,6 +30,17 @@
      */
     boolean supportsFlingToDelete();
 
+    /**
+     * @return whether items dragged from this source supports 'App Info'
+     */
+    boolean supportsAppInfoDropTarget();
+
+    /**
+     * @return whether items dragged from this source supports 'Delete' drop target (e.g. to remove
+     * a shortcut.
+     */
+    boolean supportsDeleteDropTarget();
+
     /*
      * @return the scale of the icons over the workspace icon size
      */
diff --git a/src/com/android/launcher3/Folder.java b/src/com/android/launcher3/Folder.java
index 1d234ff..50e2000 100644
--- a/src/com/android/launcher3/Folder.java
+++ b/src/com/android/launcher3/Folder.java
@@ -801,6 +801,16 @@
         return true;
     }
 
+    @Override
+    public boolean supportsAppInfoDropTarget() {
+        return false;
+    }
+
+    @Override
+    public boolean supportsDeleteDropTarget() {
+        return true;
+    }
+
     public void onFlingToDelete(DragObject d, int x, int y, PointF vec) {
         // Do nothing
     }
diff --git a/src/com/android/launcher3/InfoDropTarget.java b/src/com/android/launcher3/InfoDropTarget.java
index 2ad43b6..374238c 100644
--- a/src/com/android/launcher3/InfoDropTarget.java
+++ b/src/com/android/launcher3/InfoDropTarget.java
@@ -62,10 +62,6 @@
         }
     }
 
-    private boolean isFromAllApps(DragSource source) {
-        return (source instanceof AppsCustomizePagedView);
-    }
-
     @Override
     public boolean acceptDrop(DragObject d) {
         // acceptDrop is called just before onDrop. We do the work here, rather than
@@ -93,7 +89,7 @@
         boolean isVisible = true;
 
         // Hide this button unless we are dragging something from AllApps
-        if (!isFromAllApps(source)) {
+        if (!source.supportsAppInfoDropTarget()) {
             isVisible = false;
         }
 
diff --git a/src/com/android/launcher3/Workspace.java b/src/com/android/launcher3/Workspace.java
index 02949e7..4fd57c1 100644
--- a/src/com/android/launcher3/Workspace.java
+++ b/src/com/android/launcher3/Workspace.java
@@ -4213,6 +4213,16 @@
     }
 
     @Override
+    public boolean supportsAppInfoDropTarget() {
+        return false;
+    }
+
+    @Override
+    public boolean supportsDeleteDropTarget() {
+        return true;
+    }
+
+    @Override
     public void onFlingToDelete(DragObject d, int x, int y, PointF vec) {
         // Do nothing
     }