| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| |
| package com.android.settings.widget; |
| |
| import android.content.Context; |
| import android.graphics.Canvas; |
| import android.graphics.RectF; |
| import android.util.AttributeSet; |
| import android.util.Log; |
| import android.view.MotionEvent; |
| import android.view.View; |
| import android.view.WindowInsets; |
| import android.widget.ListView; |
| |
| /** |
| * This class provides sticky header functionality in a list view, to use with |
| * SetupWizardIllustration. To use this, add a header tagged with "sticky", or a header tagged with |
| * "stickyContainer" and one of its child tagged as "sticky". The sticky container will be drawn |
| * when the sticky element hits the top of the view. |
| * |
| * There are a few things to note: |
| * 1. The two supported scenarios are StickyHeaderListView -> Header (stickyContainer) -> sticky, |
| * and StickyHeaderListView -> Header (sticky). The arrow (->) represents parent/child |
| * relationship and must be immediate child. |
| * 2. The view does not work well with padding. b/16190933 |
| * 3. If fitsSystemWindows is true, then this will offset the sticking position by the height of |
| * the system decorations at the top of the screen. |
| * |
| * @see SetupWizardIllustration |
| * @see com.google.android.setupwizard.util.StickyHeaderScrollView |
| * |
| * Copied from com.google.android.setupwizard.util.StickyHeaderListView |
| */ |
| public class StickyHeaderListView extends ListView { |
| |
| private View mSticky; |
| private View mStickyContainer; |
| private boolean mDrawScrollBar; |
| private int mStatusBarInset = 0; |
| private RectF mStickyRect = new RectF(); |
| |
| public StickyHeaderListView(Context context) { |
| super(context); |
| } |
| |
| public StickyHeaderListView(Context context, AttributeSet attrs) { |
| super(context, attrs); |
| } |
| |
| public StickyHeaderListView(Context context, AttributeSet attrs, int defStyleAttr) { |
| super(context, attrs, defStyleAttr); |
| } |
| |
| public StickyHeaderListView(Context context, AttributeSet attrs, int defStyleAttr, |
| int defStyleRes) { |
| super(context, attrs, defStyleAttr, defStyleRes); |
| } |
| |
| @Override |
| protected void onLayout(boolean changed, int l, int t, int r, int b) { |
| super.onLayout(changed, l, t, r, b); |
| if (mSticky == null) { |
| updateStickyView(); |
| } |
| } |
| |
| public void updateStickyView() { |
| mSticky = findViewWithTag("sticky"); |
| mStickyContainer = findViewWithTag("stickyContainer"); |
| } |
| |
| @Override |
| public boolean dispatchTouchEvent(MotionEvent ev) { |
| if (mStickyRect.contains(ev.getX(), ev.getY())) { |
| ev.offsetLocation(-mStickyRect.left, -mStickyRect.top); |
| return mStickyContainer.dispatchTouchEvent(ev); |
| } else { |
| return super.dispatchTouchEvent(ev); |
| } |
| } |
| |
| @Override |
| public void draw(Canvas canvas) { |
| mDrawScrollBar = false; |
| super.draw(canvas); |
| if (mSticky != null) { |
| final int saveCount = canvas.save(); |
| // The view to draw when sticking to the top |
| final View drawTarget = mStickyContainer != null ? mStickyContainer : mSticky; |
| // The offset to draw the view at when sticky |
| final int drawOffset = mStickyContainer != null ? mSticky.getTop() : 0; |
| // Position of the draw target, relative to the outside of the scrollView |
| final int drawTop = drawTarget.getTop(); |
| if (drawTop + drawOffset < mStatusBarInset || !drawTarget.isShown()) { |
| // ListView does not translate the canvas, so we can simply draw at the top |
| canvas.translate(0, -drawOffset + mStatusBarInset); |
| canvas.clipRect(0, 0, drawTarget.getWidth(), drawTarget.getHeight()); |
| drawTarget.draw(canvas); |
| mStickyRect.set(0, -drawOffset + mStatusBarInset, drawTarget.getWidth(), |
| drawTarget.getHeight() - drawOffset + mStatusBarInset); |
| } else { |
| mStickyRect.setEmpty(); |
| } |
| canvas.restoreToCount(saveCount); |
| } |
| // Draw the scrollbars last so they are on top of the header |
| mDrawScrollBar = true; |
| onDrawScrollBars(canvas); |
| } |
| |
| @Override |
| protected boolean isVerticalScrollBarHidden() { |
| return super.isVerticalScrollBarHidden() || !mDrawScrollBar; |
| } |
| |
| @Override |
| public WindowInsets onApplyWindowInsets(WindowInsets insets) { |
| if (getFitsSystemWindows()) { |
| mStatusBarInset = insets.getSystemWindowInsetTop(); |
| insets.consumeSystemWindowInsets(false, true, false, false); |
| } |
| return insets; |
| } |
| } |