[Android] Supporting floating select ActionModes for web content

content/public/android/java/src/org/chromium/content/browser/WebActionMode.java

Index: content/public/android/java/src/org/chromium/content/browser/WebActionMode.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/WebActionMode.java b/content/public/android/java/src/org/chromium/content/browser/WebActionMode.java
index befbb81b1f5279794a6f65c0b750c90474912206..24168b1cc31866cf8818a98ebbfe1e7fe6f972c9 100644
--- a/content/public/android/java/src/org/chromium/content/browser/WebActionMode.java
+++ b/content/public/android/java/src/org/chromium/content/browser/WebActionMode.java
@@ -4,7 +4,11 @@
 
 package org.chromium.content.browser;
 
+import android.annotation.TargetApi;
+import android.os.Build;
 import android.view.ActionMode;
+import android.view.View;
+import android.view.ViewConfiguration;
 
 import org.chromium.base.Log;
 
@@ -12,18 +16,57 @@ import org.chromium.base.Log;
  * An ActionMode for in-page web content selection. This class wraps an ActionMode created
  * by the associated View, providing modified interaction with that ActionMode.
  */
+@TargetApi(Build.VERSION_CODES.M)
 public class WebActionMode {
-    private static final String TAG = "cr.SelectActionMode";
+    private static final String TAG = "cr.WebActionMode";
+
+    // Default delay for reshowing the {@link ActionMode} after it has been
+    // hidden. This avoids flickering issues if there are trailing rect
+    // invalidations after the ActionMode is shown. For example, after the user
+    // stops dragging a selection handle, in turn showing the ActionMode, the
+    // selection change response will be asynchronous. 300ms should accomodate
+    // most such trailing, async delays.
+    private static final int SHOW_DELAY_MS = 300;
 
     protected final ActionMode mActionMode;
+    private final View mView;
+    private boolean mHidden;
+    private boolean mPendingInvalidateContentRect;
+
+    // Self-repeating task that repeatedly hides the ActionMode. This is
+    // required because ActionMode only exposes a temporary hide routine.
+    private final Runnable mRepeatingHideRunnable;
 
     /**
      * Constructs a SelectActionMode instance wrapping a concrete ActionMode.
      * @param actionMode the wrapped ActionMode.
+     * @param view the associated View.
      */
-    public WebActionMode(ActionMode actionMode) {
+    public WebActionMode(ActionMode actionMode, View view) {
         assert actionMode != null;
+        assert view != null;
         mActionMode = actionMode;
+        mView = view;
+        mRepeatingHideRunnable = new Runnable() {
+            @Override
+            public void run() {
+                assert mHidden;
+                final long hideDuration = getDefaultHideDuration();
+                // Ensure the next hide call occurs before the ActionMode reappears.
+                mView.postDelayed(mRepeatingHideRunnable, hideDuration - 1);
+                hideTemporarily(hideDuration);
+            }
+        };
+    }
+
+    /**
+     * Constructs a SelectActionMode instance wrapping a concrete ActionMode.
+     * TODO(jdduke): Remove when downstream references removed.
+     * @param actionMode the wrapped ActionMode.
+     */
+    @Deprecated
+    public WebActionMode(ActionMode actionMode) {
+        this(actionMode, null);
     }
 
     /**
@@ -35,8 +78,17 @@ public class WebActionMode {
 
     /**
      * @see ActionMode#invalidate()
+     * Note that invalidation will also reset visibility state. The caller
+     * should account for this when making subsequent visibility updates.
      */
     public void invalidate() {
+        if (mHidden) {
+            assert canHide();
+            mHidden = false;
+            mView.removeCallbacks(mRepeatingHideRunnable);
+            mPendingInvalidateContentRect = false;
+        }
+
         // Try/catch necessary for framework bug, crbug.com/446717.
         try {
             mActionMode.invalidate();
@@ -48,5 +100,69 @@ public class WebActionMode {
     /**
      * @see ActionMode#invalidateContentRect()
      */
-    public void invalidateContentRect() {}
+    public void invalidateContentRect() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            if (mHidden) {
+                mPendingInvalidateContentRect = true;
+            } else {
+                mPendingInvalidateContentRect = false;
+                mActionMode.invalidateContentRect();
+            }
+        }
+    }
+
+    /**
+     * @see ActionMode#onWindowFocusChanged()
+     */
+    public void onWindowFocusChanged(boolean hasWindowFocus) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            mActionMode.onWindowFocusChanged(hasWindowFocus);
+        }
+    }
+
+    /**
+     * Hide or reveal the ActionMode. Note that this only has visible
+     * side-effects if the underlying ActionMode supports hiding.
+     * @param hide whether to hide or show the ActionMode.
+     */
+    public void hide(boolean hide) {
+        if (!canHide()) return;
+        if (mHidden == hide) return;
+        mHidden = hide;
+        if (mHidden) {
+            mRepeatingHideRunnable.run();
+        } else {
+            mHidden = false;
+            mView.removeCallbacks(mRepeatingHideRunnable);
+            hideTemporarily(SHOW_DELAY_MS);
+            if (mPendingInvalidateContentRect) {
+                mPendingInvalidateContentRect = false;
+                invalidateContentRect();
+            }
+        }
+    }
+
+    /**
+     * @see ActionMode#hide(long)
+     */
+    private void hideTemporarily(long duration) {
+        assert canHide();
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            mActionMode.hide(duration);
+        }
+    }
+
+    private boolean canHide() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            return mActionMode.getType() == ActionMode.TYPE_FLOATING;
+        }
+        return false;
+    }
+
+    private long getDefaultHideDuration() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            return ViewConfiguration.getDefaultActionModeHideDuration();
+        }
+        return 2000;
+    }
 }