chrome/android: Push EventFilters into the Layout implementations.

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/Layout.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.compositor.layouts;
 
 import static org.chromium.chrome.browser.compositor.layouts.ChromeAnimation.AnimatableAnimation.createAnimation;
 
 import android.content.Context;
 import android.graphics.PointF;
@@ skipping 81 matching lines @@
     protected TabContentManager mTabContentManager;
 
     private ChromeAnimation<Animatable<?>> mLayoutAnimations;
 
     // Tablet tab strip managers.
     private final List<SceneOverlay> mSceneOverlays = new ArrayList<SceneOverlay>();
 
     // Helpers
     private final LayoutUpdateHost mUpdateHost;
     protected final LayoutRenderHost mRenderHost;
-    private EventFilter mEventFilter;
+    protected EventFilter mEventFilter;

[Khushal, 2017/03/22 21:20:09]

I was thinking about just removing this and adding a getEventFilter() which lets
the sub-class provide the EventFilter. May be not worth it.

[mdjones, 2017/03/23 17:18:55]

I think this is a pretty good idea; it makes the event filter feel more like a
requirement rather than an implementation detail. I guess it depends on how you
look at it though. It seems like each layout should be responsible for its own.

[David Trainor- moved to gerrit, 2017/03/24 17:06:43]

getEventFilter makes sense if you want the subclass to create and own it.  It's
a cleaner API :).  You might want to allow them to return null though (e.g.
default behavior could be pass through or 'black hole').

[Khushal, 2017/03/24 22:33:09]

Done. StaticLayout returns null because it only takes gestures from the toolbar.
Otherwise it passes through to the content. The rest that want to eat up all
events do the BlackHole one.

 
     /** The tabs currently being rendered as part of this layout. The tabs are
      * drawn using the same ordering as this array. */
     protected LayoutTab[] mLayoutTabs;
 
     // True means that the layout is going to hide as soon as the animation finishes.
     private boolean mIsHiding;
 
     // The next id to show when the layout is hidden, or TabBase#INVALID_TAB_ID if no change.
     private int mNextTabId = Tab.INVALID_TAB_ID;
 
     // The ratio of dp to px.
     private final float mDpToPx;
 
     /**
      * The {@link Layout} is not usable until sizeChanged is called.
      * This is convenient this way so we can pre-create the layout before the host is fully defined.
      * @param context      The current Android's context.
      * @param updateHost   The parent {@link LayoutUpdateHost}.
      * @param renderHost   The parent {@link LayoutRenderHost}.
-     * @param eventFilter  The {@link EventFilter} this {@link Layout} is listening to.
      */
-    public Layout(Context context, LayoutUpdateHost updateHost, LayoutRenderHost renderHost,
-            EventFilter eventFilter) {
+    public Layout(Context context, LayoutUpdateHost updateHost, LayoutRenderHost renderHost) {
         mContext = context;
         mUpdateHost = updateHost;
         mRenderHost = renderHost;
-        mEventFilter = eventFilter;
 
         // Invalid sizes
         mWidthDp = -1;
         mHeightDp = -1;
         mHeightMinusBrowserControlsDp = -1;
 
         mCurrentOrientation = Orientation.UNSET;
         mDpToPx = context.getResources().getDisplayMetrics().density;
     }
 
@@ skipping 424 matching lines @@
      */
     protected boolean initLayoutTabFromHost(LayoutTab layoutTab) {
         if (layoutTab.isInitFromHostNeeded()) {
             mUpdateHost.initLayoutTabFromHost(layoutTab.getId());
             return true;
         }
         return false;
     }
 
     /**
-     * Called on touch drag event.
-     * @param time      The current time of the app in ms.
-     * @param x         The y coordinate of the end of the drag event.
-     * @param y         The y coordinate of the end of the drag event.
-     * @param deltaX    The number of pixels dragged in the x direction.
-     * @param deltaY    The number of pixels dragged in the y direction.
-     */
-    public void drag(long time, float x, float y, float deltaX, float deltaY) { }
-
-    /**
-     * Called on touch fling event. This is called before the onUpOrCancel event.
-     *
-     * @param time      The current time of the app in ms.
-     * @param x         The y coordinate of the start of the fling event.
-     * @param y         The y coordinate of the start of the fling event.
-     * @param velocityX The amount of velocity in the x direction.
-     * @param velocityY The amount of velocity in the y direction.
-     */
-    public void fling(long time, float x, float y, float velocityX, float velocityY) { }
-
-    /**
-     * Called on onDown event.
-     *
-     * @param time      The time stamp in millisecond of the event.
-     * @param x         The x position of the event.
-     * @param y         The y position of the event.
-     */
-    public void onDown(long time, float x, float y) { }
-
-    /**
-     * Called on long press touch event.
-     * @param time The current time of the app in ms.
-     * @param x    The x coordinate of the position of the press event.
-     * @param y    The y coordinate of the position of the press event.
-     */
-    public void onLongPress(long time, float x, float y) { }
-
-    /**
-     * Called on click. This is called before the onUpOrCancel event.
-     * @param time The current time of the app in ms.
-     * @param x    The x coordinate of the position of the click.
-     * @param y    The y coordinate of the position of the click.
-     */
-    public void click(long time, float x, float y) { }
-
-    /**
-     * Called on up or cancel touch events. This is called after the click and fling event if any.
-     * @param time The current time of the app in ms.
-     */
-    public void onUpOrCancel(long time) { }
-
-    /**
-     * Called when at least 2 touch events are detected.
-     * @param time       The current time of the app in ms.
-     * @param x0         The x coordinate of the first touch event.
-     * @param y0         The y coordinate of the first touch event.
-     * @param x1         The x coordinate of the second touch event.
-     * @param y1         The y coordinate of the second touch event.
-     * @param firstEvent The pinch is the first of a sequence of pinch events.
-     */
-    public void onPinch(long time, float x0, float y0, float x1, float y1, boolean firstEvent) { }
-
-    /**
      * Called by the LayoutManager when an animation should be killed.
      */
     public void unstallImmediately() { }
 
     /**
      * Called by the LayoutManager when an animation should be killed.
      * @param tabId The tab that the kill signal is associated with
      */
     public void unstallImmediately(int tabId) { }
 
@@ skipping 383 matching lines @@
     }
 
     /**
      * @return True if the currently active content view is shown in the normal interactive mode.
      */
     public boolean isTabInteractive() {
         return false;
     }
 
     /**
-     * Setting this will only take effect the next time this layout is shown.  If it is currently
-     * showing the original filter will still be used.
-     * @param filter
-     */
-    public void setEventFilter(EventFilter filter) {
-        mEventFilter = filter;
-    }
-
-    /**
      * @param e                 The {@link MotionEvent} to consider.
      * @param offsets           The current touch offsets that should be applied to the
      *                          {@link EventFilter}s.
      * @param isKeyboardShowing Whether or not the keyboard is showing.
      * @return The {@link EventFilter} the {@link Layout} is listening to.
      */
     public EventFilter findInterceptingEventFilter(
             MotionEvent e, PointF offsets, boolean isKeyboardShowing) {
         // The last added overlay will be drawn on top of everything else, therefore the last
         // filter added should have the first chance to intercept any touch events.
@@ skipping 60 matching lines @@
     }
 
     /**
      * @return Whether or not the layout should permenantly show the browser controls.
      */
     public boolean forceShowBrowserControlsAndroidView() {
         return false;
     }
 
     /**
-     * @return Whether the tabstrip's event filter is enabled.
-     */
-    public boolean isTabStripEventFilterEnabled() {

[Khushal, 2017/03/22 21:20:09]

This would always return true, so not necessary.

[mdjones, 2017/03/23 17:18:55]

Also this had no place in this class and apparently was never overridden.

-        return true;
-    }
-
-    /**
      * Get an instance of {@link SceneLayer}. Any class inheriting {@link Layout}
      * should override this function in order for other functions to work.
      *
      * @return The scene layer for this {@link Layout}.
      */
     protected abstract SceneLayer getSceneLayer();
 
     /**
      * Update {@link SceneLayer} instance this layout holds. Any class inheriting {@link Layout}
      * should override this function in order for other functions to work.
      */
     protected void updateSceneLayer(RectF viewport, RectF contentViewport,
             LayerTitleCache layerTitleCache, TabContentManager tabContentManager,
             ResourceManager resourceManager, ChromeFullscreenManager fullscreenManager) {
     }
 }