1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mobile/android/base/home/TabMenuStripLayout.java Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,194 @@
1.4 +/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +package org.mozilla.gecko.home;
1.10 +
1.11 +import org.mozilla.gecko.R;
1.12 +
1.13 +import android.content.Context;
1.14 +import android.content.res.TypedArray;
1.15 +import android.graphics.Canvas;
1.16 +import android.graphics.drawable.Drawable;
1.17 +import android.util.AttributeSet;
1.18 +import android.view.LayoutInflater;
1.19 +import android.view.View;
1.20 +import android.view.ViewTreeObserver;
1.21 +import android.view.accessibility.AccessibilityEvent;
1.22 +import android.widget.LinearLayout;
1.23 +import android.widget.TextView;
1.24 +
1.25 +/**
1.26 + * {@code TabMenuStripLayout} is the view that draws the {@code HomePager}
1.27 + * tabs that are displayed in {@code TabMenuStrip}.
1.28 + */
1.29 +class TabMenuStripLayout extends LinearLayout
1.30 + implements View.OnFocusChangeListener {
1.31 +
1.32 + private HomePager.OnTitleClickListener onTitleClickListener;
1.33 + private Drawable strip;
1.34 + private View selectedView;
1.35 +
1.36 + // Data associated with the scrolling of the strip drawable.
1.37 + private View toTab;
1.38 + private View fromTab;
1.39 + private float progress;
1.40 +
1.41 + // This variable is used to predict the direction of scroll.
1.42 + private float prevProgress;
1.43 +
1.44 + TabMenuStripLayout(Context context, AttributeSet attrs) {
1.45 + super(context, attrs);
1.46 +
1.47 + TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.TabMenuStrip);
1.48 + final int stripResId = a.getResourceId(R.styleable.TabMenuStrip_strip, -1);
1.49 + a.recycle();
1.50 +
1.51 + if (stripResId != -1) {
1.52 + strip = getResources().getDrawable(stripResId);
1.53 + }
1.54 +
1.55 + setWillNotDraw(false);
1.56 + }
1.57 +
1.58 + void onAddPagerView(String title) {
1.59 + final TextView button = (TextView) LayoutInflater.from(getContext()).inflate(R.layout.tab_menu_strip, this, false);
1.60 + button.setText(title.toUpperCase());
1.61 +
1.62 + addView(button);
1.63 + button.setOnClickListener(new ViewClickListener(getChildCount() - 1));
1.64 + button.setOnFocusChangeListener(this);
1.65 + }
1.66 +
1.67 + void onPageSelected(final int position) {
1.68 + selectedView = getChildAt(position);
1.69 +
1.70 + // Callback to measure and draw the strip after the view is visible.
1.71 + ViewTreeObserver vto = selectedView.getViewTreeObserver();
1.72 + if (vto.isAlive()) {
1.73 + vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
1.74 + @Override
1.75 + public void onGlobalLayout() {
1.76 + selectedView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
1.77 +
1.78 + if (strip != null) {
1.79 + strip.setBounds(selectedView.getLeft(),
1.80 + selectedView.getTop(),
1.81 + selectedView.getRight(),
1.82 + selectedView.getBottom());
1.83 + }
1.84 +
1.85 + prevProgress = position;
1.86 + }
1.87 + });
1.88 + }
1.89 + }
1.90 +
1.91 + // Page scroll animates the drawable and its bounds from the previous to next child view.
1.92 + void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
1.93 + if (strip == null) {
1.94 + return;
1.95 + }
1.96 +
1.97 + setScrollingData(position, positionOffset);
1.98 +
1.99 + if (fromTab == null || toTab == null) {
1.100 + return;
1.101 + }
1.102 +
1.103 + final int fromTabLeft = fromTab.getLeft();
1.104 + final int fromTabRight = fromTab.getRight();
1.105 +
1.106 + final int toTabLeft = toTab.getLeft();
1.107 + final int toTabRight = toTab.getRight();
1.108 +
1.109 + strip.setBounds((int) (fromTabLeft + ((toTabLeft - fromTabLeft) * progress)),
1.110 + 0,
1.111 + (int) (fromTabRight + ((toTabRight - fromTabRight) * progress)),
1.112 + getHeight());
1.113 + invalidate();
1.114 + }
1.115 +
1.116 + /*
1.117 + * position + positionOffset goes from 0 to 2 as we scroll from page 1 to 3.
1.118 + * Normalized progress is relative to the the direction the page is being scrolled towards.
1.119 + * For this, we maintain direction of scroll with a state, and the child view we are moving towards and away from.
1.120 + */
1.121 + void setScrollingData(int position, float positionOffset) {
1.122 + if (position >= getChildCount() - 1) {
1.123 + return;
1.124 + }
1.125 +
1.126 + final float currProgress = position + positionOffset;
1.127 +
1.128 + if (prevProgress > currProgress) {
1.129 + toTab = getChildAt(position);
1.130 + fromTab = getChildAt(position + 1);
1.131 + progress = 1 - positionOffset;
1.132 + } else {
1.133 + toTab = getChildAt(position + 1);
1.134 + fromTab = getChildAt(position);
1.135 + progress = positionOffset;
1.136 + }
1.137 +
1.138 + prevProgress = currProgress;
1.139 + }
1.140 +
1.141 + @Override
1.142 + public void onDraw(Canvas canvas) {
1.143 + super.onDraw(canvas);
1.144 +
1.145 + if (strip != null) {
1.146 + strip.draw(canvas);
1.147 + }
1.148 + }
1.149 +
1.150 + @Override
1.151 + public void onFocusChange(View v, boolean hasFocus) {
1.152 + if (v == this && hasFocus && getChildCount() > 0) {
1.153 + selectedView.requestFocus();
1.154 + return;
1.155 + }
1.156 +
1.157 + if (!hasFocus) {
1.158 + return;
1.159 + }
1.160 +
1.161 + int i = 0;
1.162 + final int numTabs = getChildCount();
1.163 +
1.164 + while (i < numTabs) {
1.165 + View view = getChildAt(i);
1.166 + if (view == v) {
1.167 + view.requestFocus();
1.168 + if (isShown()) {
1.169 + // A view is focused so send an event to announce the menu strip state.
1.170 + sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_FOCUSED);
1.171 + }
1.172 + break;
1.173 + }
1.174 +
1.175 + i++;
1.176 + }
1.177 + }
1.178 +
1.179 + void setOnTitleClickListener(HomePager.OnTitleClickListener onTitleClickListener) {
1.180 + this.onTitleClickListener = onTitleClickListener;
1.181 + }
1.182 +
1.183 + private class ViewClickListener implements OnClickListener {
1.184 + private final int mIndex;
1.185 +
1.186 + public ViewClickListener(int index) {
1.187 + mIndex = index;
1.188 + }
1.189 +
1.190 + @Override
1.191 + public void onClick(View view) {
1.192 + if (onTitleClickListener != null) {
1.193 + onTitleClickListener.onTitleClicked(mIndex);
1.194 + }
1.195 + }
1.196 + }
1.197 +}
