Stylus support: creating and setting listeners for stylus button press
This updates almost(*) all locations that use a long press listener to
also set a custom touch listener that recognizes the stylus button press
action.
The stylus button press action is: when a stylus touches a view while the
primary stylus button is pressed which may occur on a DOWN or MOVE event.
*The location this is *not* enabled for is: Longpress to enter "overview"
mode -- this isn't really a selection or drag n drop action; it is also
easy to accidentally do this while using the stylus gesture to drag n drop
items which is not an ideal interaction. Also not set for the "cling" that
demonstrates this.
Bug: 20430722
Change-Id: I9343f143261a7b4fada9afca28b8a11a60dbecca
diff --git a/src/com/android/launcher3/StylusEventHelper.java b/src/com/android/launcher3/StylusEventHelper.java
new file mode 100644
index 0000000..da46e6a
--- /dev/null
+++ b/src/com/android/launcher3/StylusEventHelper.java
@@ -0,0 +1,84 @@
+package com.android.launcher3;
+
+import com.android.launcher3.Utilities;
+
+import android.util.Log;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewConfiguration;
+
+/**
+ * Helper for identifying when a stylus touches a view while the primary stylus button is pressed.
+ * This can occur in {@value MotionEvent#ACTION_DOWN} or {@value MotionEvent#ACTION_MOVE}. On a
+ * stylus button press this performs the view's {@link View#performLongClick()} method, if the view
+ * is long clickable.
+ */
+public class StylusEventHelper {
+ private boolean mIsButtonPressed;
+ private View mView;
+
+ public StylusEventHelper(View view) {
+ mView = view;
+ }
+
+ /**
+ * Call this in onTouchEvent method of a view to identify a stylus button press and perform a
+ * long click (if the view is long clickable).
+ *
+ * @param event The event to check for a stylus button press.
+ * @return Whether a stylus event occurred and was handled.
+ */
+ public boolean checkAndPerformStylusEvent(MotionEvent event) {
+ final float slop = ViewConfiguration.get(mView.getContext()).getScaledTouchSlop();
+
+ if (!mView.isLongClickable()) {
+ // We don't do anything unless the view is long clickable.
+ return false;
+ }
+
+ final boolean stylusButtonPressed = isStylusButtonPressed(event);
+ switch (event.getAction()) {
+ case MotionEvent.ACTION_DOWN:
+ mIsButtonPressed = false;
+ if (stylusButtonPressed && mView.performLongClick()) {
+ mIsButtonPressed = true;
+ return true;
+ }
+ break;
+ case MotionEvent.ACTION_MOVE:
+ if (Utilities.pointInView(mView, event.getX(), event.getY(), slop)) {
+ if (!mIsButtonPressed && stylusButtonPressed && mView.performLongClick()) {
+ mIsButtonPressed = true;
+ return true;
+ } else if (mIsButtonPressed && !stylusButtonPressed) {
+ mIsButtonPressed = false;
+ }
+ }
+ break;
+ case MotionEvent.ACTION_UP:
+ case MotionEvent.ACTION_CANCEL:
+ mIsButtonPressed = false;
+ break;
+ }
+ return false;
+ }
+
+ /**
+ * Whether a stylus button press is occurring.
+ */
+ public boolean inStylusButtonPressed() {
+ return mIsButtonPressed;
+ }
+
+ /**
+ * Identifies if the provided {@link MotionEvent} is a stylus with the primary stylus button
+ * pressed.
+ *
+ * @param event The event to check.
+ * @return Whether a stylus button press occurred.
+ */
+ public static boolean isStylusButtonPressed(MotionEvent event) {
+ return event.getToolType(0) == MotionEvent.TOOL_TYPE_STYLUS
+ && event.isButtonPressed(MotionEvent.BUTTON_SECONDARY);
+ }
+}
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