commit b66675a36d5daec4aea4470cb5c804c54edb06cd
author Adam Cohen <adamcohen@google.com> Fri May 15 16:16:17 2020 -0700
committer Adam Cohen <adamcohen@google.com> Fri May 15 16:57:37 2020 -0700
tree a68aff93dcebf71d3749de28f3b9f216a28ee6cf
parent 2d78b783cc244455260201f7a48e2d3e758de39c

Delegate horizontal scrolls from the Hotseat to the Workspace

=> Before this change, scrolling horizontally on the the hotseat area was a no-op
=> This is a mild usability issue (or arguably WAI) for the default grid, but for larger grids it feels really broken as you have to reach very high just to scroll to another page.

issue 156507399

Test: manual. Also verified that swipe up still works and goes through the same code path.

Change-Id: I760aca473dd36bc8cfb906cb58e897e2ab7fd1d9

src/com/android/launcher3/Hotseat.java

diff --git a/src/com/android/launcher3/Hotseat.java b/src/com/android/launcher3/Hotseat.java
index be941f2..1c157c2 100644
--- a/src/com/android/launcher3/Hotseat.java
+++ b/src/com/android/launcher3/Hotseat.java
@@ -38,6 +38,8 @@
 
     @ViewDebug.ExportedProperty(category = "launcher")
     private boolean mHasVerticalHotseat;
+    private Workspace mWorkspace;
+    private boolean mSendTouchToWorkspace;
 
     public Hotseat(Context context) {
         this(context, null);
@@ -112,8 +114,35 @@
         InsettableFrameLayout.dispatchInsets(this, insets);
     }
 
+    public void setWorkspace(Workspace w) {
+        mWorkspace = w;
+    }
+
+    @Override
+    public boolean onInterceptTouchEvent(MotionEvent ev) {
+        // We allow horizontal workspace scrolling from within the Hotseat. We do this by delegating
+        // touch intercept the Workspace, and if it intercepts, delegating touch to the Workspace
+        // for the remainder of the this input stream.
+        int yThreshold = getMeasuredHeight() - getPaddingBottom();
+        if (mWorkspace != null && ev.getY() <= yThreshold) {
+            mSendTouchToWorkspace = mWorkspace.onInterceptTouchEvent(ev);
+            return mSendTouchToWorkspace;
+        }
+        return false;
+    }
+
     @Override
     public boolean onTouchEvent(MotionEvent event) {
+        // See comment in #onInterceptTouchEvent
+        if (mSendTouchToWorkspace) {
+            final int action = event.getAction();
+            switch (action & MotionEvent.ACTION_MASK) {
+                case MotionEvent.ACTION_UP:
+                case MotionEvent.ACTION_CANCEL:
+                    mSendTouchToWorkspace = false;
+            }
+            return mWorkspace.onTouchEvent(event);
+        }
         return event.getY() > getCellHeight();
     }
 }

src/com/android/launcher3/Launcher.java

diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 59476dd..1f84c42 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -1116,6 +1116,7 @@
         mWorkspace.initParentViews(mDragLayer);
         mOverviewPanel = findViewById(R.id.overview_panel);
         mHotseat = findViewById(R.id.hotseat);
+        mHotseat.setWorkspace(mWorkspace);
 
         mLauncherView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                 | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION