// Copyright 2014 The Chromium Authors
// 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.ui.appmenu;
import android.animation.TimeAnimator;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Rect;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.widget.ImageButton;
import android.widget.LinearLayout;
import android.widget.ListView;
import androidx.annotation.IntDef;
import androidx.annotation.VisibleForTesting;
import org.chromium.base.metrics.RecordUserAction;
import org.chromium.chrome.browser.ui.appmenu.internal.R;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.ArrayList;
/**
* Handles the drag touch events on AppMenu that start from the menu button.
*
* Lint suppression for NewApi is added because we are using TimeAnimator class that was marked
* hidden in API 16.
*/
@SuppressLint("NewApi")
class AppMenuDragHelper {
private final Context mContext;
private final AppMenu mAppMenu;
// Internally used action constants for dragging.
@IntDef({ItemAction.HIGHLIGHT, ItemAction.PERFORM, ItemAction.CLEAR_HIGHLIGHT_ALL})
@Retention(RetentionPolicy.SOURCE)
private @interface ItemAction {
int HIGHLIGHT = 0;
int PERFORM = 1;
int CLEAR_HIGHLIGHT_ALL = 2;
}
private static final float AUTO_SCROLL_AREA_MAX_RATIO = 0.25f;
// Dragging related variables, i.e., menu showing initiated by touch down and drag to navigate.
private final float mAutoScrollFullVelocity;
private final TimeAnimator mDragScrolling = new TimeAnimator();
private float mDragScrollOffset;
private int mDragScrollOffsetRounded;
private volatile float mDragScrollingVelocity;
private volatile float mLastTouchX;
private volatile float mLastTouchY;
private final int mItemRowHeight;
private boolean mIsSingleTapCanceled;
private boolean mMoved;
private int mMenuButtonScreenCenterY;
// These are used in a function locally, but defined here to avoid heap allocation on every
// touch event.
private final Rect mScreenVisibleRect = new Rect();
private final int[] mScreenVisiblePoint = new int[2];
private final int mTapTimeout;
private final int mScaledTouchSlop;
AppMenuDragHelper(Context context, AppMenu appMenu, int itemRowHeight) {
mContext = context;
mAppMenu = appMenu;
mItemRowHeight = itemRowHeight;
Resources res = mContext.getResources();
mAutoScrollFullVelocity = res.getDimensionPixelSize(R.dimen.auto_scroll_full_velocity);
// If user is dragging and the popup ListView is too big to display at once,
// mDragScrolling animator scrolls mPopup.getListView() automatically depending on
// the user's touch position.
mDragScrolling.setTimeListener(
(animation, totalTime, deltaTime) -> {
if (mAppMenu.getListView() == null) return;
// We keep both mDragScrollOffset and mDragScrollOffsetRounded because
// the actual scrolling is by the rounded value but at the same time we also
// want to keep the precise scroll value in float.
mDragScrollOffset += (deltaTime * 0.001f) * mDragScrollingVelocity;
int diff = Math.round(mDragScrollOffset - mDragScrollOffsetRounded);
mDragScrollOffsetRounded += diff;
mAppMenu.getListView().smoothScrollBy(diff, 0);
// Force touch move event to highlight items correctly for the scrolled
// position.
if (!Float.isNaN(mLastTouchX) && !Float.isNaN(mLastTouchY)) {
menuItemAction(
Math.round(mLastTouchX),
Math.round(mLastTouchY),
ItemAction.HIGHLIGHT);
}
});
// We use medium timeout, the average of tap and long press timeouts. This is consistent
// with ListPopupWindow#ForwardingListener implementation.
mTapTimeout =
(ViewConfiguration.getTapTimeout() + ViewConfiguration.getLongPressTimeout()) / 2;
mScaledTouchSlop = ViewConfiguration.get(mContext).getScaledTouchSlop();
}
/**
* Sets up all the internal state to prepare for menu dragging.
* @param startDragging Whether dragging is started. For example, if the app menu
* is showed by tapping on a button, this should be false. If it is
* showed by start dragging down on the menu button, this should be
* true.
*/
void onShow(boolean startDragging) {
mLastTouchX = Float.NaN;
mLastTouchY = Float.NaN;
mDragScrollOffset = 0.0f;
mDragScrollOffsetRounded = 0;
mDragScrollingVelocity = 0.0f;
mIsSingleTapCanceled = false;
mMoved = false;
if (startDragging) mDragScrolling.start();
}
/**
* Dragging mode will be stopped by calling this function. Note that it will fall back to normal
* non-dragging mode.
*/
void finishDragging() {
// If the menu is being dismissed, we cannot access mAppMenu.getPopup().getListView()
// needed to by menuItemAction. Only clear highlighting if the menu is still showing.
// See crbug.com/589805.
if (mAppMenu.getPopup().isShowing()) {
menuItemAction(0, 0, ItemAction.CLEAR_HIGHLIGHT_ALL);
}
mDragScrolling.cancel();
}
/**
* Gets all the touch events and updates dragging related logic. Note that if this app menu
* is initiated by software UI control, then the control should set onTouchListener and forward
* all the events to this method because the initial UI control that processed ACTION_DOWN will
* continue to get all the subsequent events.
*
* @param event Touch event to be processed.
* @param button Button that received the touch event.
* @return Whether the event is handled.
*/
boolean handleDragging(MotionEvent event, View button) {
if (!mAppMenu.isShowing() || !mDragScrolling.isRunning()) return false;
// We will only use the screen space coordinate (rawX, rawY) to reduce confusion.
// This code works across many different controls, so using local coordinates will be
// a disaster.
final float rawX = event.getRawX();
final float rawY = event.getRawY();
final int roundedRawX = Math.round(rawX);
final int roundedRawY = Math.round(rawY);
final int eventActionMasked = event.getActionMasked();
final long timeSinceDown = event.getEventTime() - event.getDownTime();
final ListView listView = mAppMenu.getListView();
mLastTouchX = rawX;
mLastTouchY = rawY;
mMenuButtonScreenCenterY = getScreenVisibleRect(button).centerY();
if (eventActionMasked == MotionEvent.ACTION_CANCEL) {
mAppMenu.dismiss();
return true;
}
if (eventActionMasked == MotionEvent.ACTION_MOVE) {
mMoved = true;
}
mIsSingleTapCanceled |= timeSinceDown > mTapTimeout;
mIsSingleTapCanceled |= !pointInView(button, event.getX(), event.getY(), mScaledTouchSlop);
if (eventActionMasked == MotionEvent.ACTION_UP && (!mMoved || !mIsSingleTapCanceled)) {
RecordUserAction.record("MobileUsingMenuBySwButtonTap");
finishDragging();
}
// After this line, drag scrolling is happening.
if (!mDragScrolling.isRunning()) return false;
boolean didPerformClick = false;
@ItemAction int itemAction = ItemAction.CLEAR_HIGHLIGHT_ALL;
switch (eventActionMasked) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_MOVE:
itemAction = ItemAction.HIGHLIGHT;
break;
case MotionEvent.ACTION_UP:
itemAction = ItemAction.PERFORM;
break;
default:
break;
}
didPerformClick = menuItemAction(roundedRawX, roundedRawY, itemAction);
if (eventActionMasked == MotionEvent.ACTION_UP && !didPerformClick) {
RecordUserAction.record("MobileUsingMenuBySwButtonDragging");
mAppMenu.dismiss();
} else if (eventActionMasked == MotionEvent.ACTION_MOVE) {
// Auto scrolling on the top or the bottom of the listView.
if (listView.getHeight() > 0) {
float autoScrollAreaRatio =
Math.min(
AUTO_SCROLL_AREA_MAX_RATIO,
mItemRowHeight * 1.2f / listView.getHeight());
float normalizedY =
(rawY - getScreenVisibleRect(listView).top) / listView.getHeight();
if (normalizedY < autoScrollAreaRatio) {
// Top
mDragScrollingVelocity =
(normalizedY / autoScrollAreaRatio - 1.0f) * mAutoScrollFullVelocity;
} else if (normalizedY > 1.0f - autoScrollAreaRatio) {
// Bottom
mDragScrollingVelocity =
((normalizedY - 1.0f) / autoScrollAreaRatio + 1.0f)
* mAutoScrollFullVelocity;
} else {
// Middle or not scrollable.
mDragScrollingVelocity = 0.0f;
}
}
}
return true;
}
private boolean pointInView(View view, float x, float y, float slop) {
return x >= -slop
&& y >= -slop
&& x < (view.getWidth() + slop)
&& y < (view.getHeight() + slop);
}
/**
* Performs the specified action on the menu item specified by the screen coordinate position.
* @param screenX X in screen space coordinate.
* @param screenY Y in screen space coordinate.
* @param action Action type to perform, it should be one of ITEM_ACTION_* constants.
* @return true whether or not a menu item is performed (executed).
*/
private boolean menuItemAction(int screenX, int screenY, @ItemAction int action) {
if (!isReadyForMenuItemAction()) return false;
ListView listView = mAppMenu.getListView();
ArrayList<View> itemViews = new ArrayList<View>();
for (int i = 0; i < listView.getChildCount(); ++i) {
boolean hasImageButtons = false;
if (listView.getChildAt(i) instanceof LinearLayout) {
LinearLayout layout = (LinearLayout) listView.getChildAt(i);
for (int j = 0; j < layout.getChildCount(); ++j) {
itemViews.add(layout.getChildAt(j));
if (layout.getChildAt(j) instanceof ImageButton) hasImageButtons = true;
}
}
if (!hasImageButtons) itemViews.add(listView.getChildAt(i));
}
boolean didPerformClick = false;
for (int i = 0; i < itemViews.size(); ++i) {
View itemView = itemViews.get(i);
boolean shouldPerform =
itemView.isEnabled()
&& itemView.isShown()
&& getScreenVisibleRect(itemView).contains(screenX, screenY);
switch (action) {
case ItemAction.HIGHLIGHT:
itemView.setPressed(shouldPerform);
break;
case ItemAction.PERFORM:
if (shouldPerform) {
RecordUserAction.record("MobileUsingMenuBySwButtonDragging");
itemView.performClick();
didPerformClick = true;
}
break;
case ItemAction.CLEAR_HIGHLIGHT_ALL:
itemView.setPressed(false);
break;
default:
assert false;
break;
}
}
return didPerformClick;
}
/**
* @return Visible rect in screen coordinates for the given View.
*/
@VisibleForTesting
Rect getScreenVisibleRect(View view) {
view.getLocalVisibleRect(mScreenVisibleRect);
view.getLocationOnScreen(mScreenVisiblePoint);
mScreenVisibleRect.offset(mScreenVisiblePoint[0], mScreenVisiblePoint[1]);
return mScreenVisibleRect;
}
@VisibleForTesting
boolean isReadyForMenuItemAction() {
ListView listView = mAppMenu.getListView();
// Starting M, we have a popup menu animation that slides down. If we process dragging
// events while it's sliding, it will touch many views that are passing by user's finger,
// which is not desirable. So we only process when the first item is below the menu button.
// Unfortunately, there is no available listener for sliding animation finished. Thus the
// following nasty heuristics.
final View firstRow = listView.getChildAt(0);
if (listView.getFirstVisiblePosition() == 0
&& firstRow != null
&& firstRow.getTop() == 0
&& getScreenVisibleRect(firstRow).bottom <= mMenuButtonScreenCenterY) {
return false;
}
return true;
}
}
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