1 /* 2 * Copyright (C) 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.android.launcher3.allapps; 17 18 import android.content.Context; 19 import android.util.AttributeSet; 20 import android.view.MotionEvent; 21 22 import com.android.launcher3.PagedView; 23 24 public class AllAppsPagedView extends PagedView<PersonalWorkSlidingTabStrip> { 25 26 final static float START_DAMPING_TOUCH_SLOP_ANGLE = (float) Math.PI / 6; 27 final static float MAX_SWIPE_ANGLE = (float) Math.PI / 3; 28 final static float TOUCH_SLOP_DAMPING_FACTOR = 4; 29 AllAppsPagedView(Context context)30 public AllAppsPagedView(Context context) { 31 this(context, null); 32 } 33 AllAppsPagedView(Context context, AttributeSet attrs)34 public AllAppsPagedView(Context context, AttributeSet attrs) { 35 this(context, attrs, 0); 36 } 37 AllAppsPagedView(Context context, AttributeSet attrs, int defStyle)38 public AllAppsPagedView(Context context, AttributeSet attrs, int defStyle) { 39 super(context, attrs, defStyle); 40 } 41 42 @Override getCurrentPageDescription()43 protected String getCurrentPageDescription() { 44 // Not necessary, tab-bar already has two tabs with their own descriptions. 45 return ""; 46 } 47 48 @Override onScrollChanged(int l, int t, int oldl, int oldt)49 protected void onScrollChanged(int l, int t, int oldl, int oldt) { 50 super.onScrollChanged(l, t, oldl, oldt); 51 mPageIndicator.setScroll(l, mMaxScrollX); 52 } 53 54 @Override determineScrollingStart(MotionEvent ev)55 protected void determineScrollingStart(MotionEvent ev) { 56 float absDeltaX = Math.abs(ev.getX() - getDownMotionX()); 57 float absDeltaY = Math.abs(ev.getY() - getDownMotionY()); 58 59 if (Float.compare(absDeltaX, 0f) == 0) return; 60 61 float slope = absDeltaY / absDeltaX; 62 float theta = (float) Math.atan(slope); 63 64 if (absDeltaX > mTouchSlop || absDeltaY > mTouchSlop) { 65 cancelCurrentPageLongPress(); 66 } 67 68 if (theta > MAX_SWIPE_ANGLE) { 69 return; 70 } else if (theta > START_DAMPING_TOUCH_SLOP_ANGLE) { 71 theta -= START_DAMPING_TOUCH_SLOP_ANGLE; 72 float extraRatio = (float) 73 Math.sqrt((theta / (MAX_SWIPE_ANGLE - START_DAMPING_TOUCH_SLOP_ANGLE))); 74 super.determineScrollingStart(ev, 1 + TOUCH_SLOP_DAMPING_FACTOR * extraRatio); 75 } else { 76 super.determineScrollingStart(ev); 77 } 78 } 79 80 @Override hasOverlappingRendering()81 public boolean hasOverlappingRendering() { 82 return false; 83 } 84 } 85