gecko/mobile/android/base/home/TabMenuStrip.java

207 lines
6.5 KiB
Java

/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.gecko.home;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.graphics.Rect;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.accessibility.AccessibilityEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewParent;
import android.view.ViewTreeObserver;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.util.Log;
import org.mozilla.gecko.home.HomePager;
import org.mozilla.gecko.R;
public class TabMenuStrip extends LinearLayout
implements HomePager.Decor,
View.OnFocusChangeListener {
private static final String LOGTAG = "GeckoTabMenuStrip";
private HomePager.OnTitleClickListener mOnTitleClickListener;
private Drawable mStrip;
private View mSelectedView;
// Data associated with the scrolling of the strip drawable.
private View toTab;
private View fromTab;
private float progress;
// This variable is used to predict the direction of scroll.
private float mPrevProgress;
public TabMenuStrip(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.TabMenuStrip);
final int stripResId = a.getResourceId(R.styleable.TabMenuStrip_strip, -1);
a.recycle();
if (stripResId != -1) {
mStrip = getResources().getDrawable(stripResId);
}
setWillNotDraw(false);
}
@Override
public void onAddPagerView(String title) {
final TextView button = (TextView) LayoutInflater.from(getContext()).inflate(R.layout.tab_menu_strip, this, false);
button.setText(title.toUpperCase());
addView(button);
button.setOnClickListener(new ViewClickListener(getChildCount() - 1));
button.setOnFocusChangeListener(this);
}
@Override
public void removeAllPagerViews() {
removeAllViews();
}
@Override
public void onPageSelected(final int position) {
mSelectedView = getChildAt(position);
// Callback to measure and draw the strip after the view is visible.
ViewTreeObserver vto = mSelectedView.getViewTreeObserver();
if (vto.isAlive()) {
vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
mSelectedView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
if (mStrip != null) {
mStrip.setBounds(mSelectedView.getLeft(),
mSelectedView.getTop(),
mSelectedView.getRight(),
mSelectedView.getBottom());
}
mPrevProgress = position;
}
});
}
}
// Page scroll animates the drawable and its bounds from the previous to next child view.
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
if (mStrip == null) {
return;
}
setScrollingData(position, positionOffset);
if (fromTab == null || toTab == null) {
return;
}
final int fromTabLeft = fromTab.getLeft();
final int fromTabRight = fromTab.getRight();
final int toTabLeft = toTab.getLeft();
final int toTabRight = toTab.getRight();
mStrip.setBounds((int) (fromTabLeft + ((toTabLeft - fromTabLeft) * progress)),
0,
(int) (fromTabRight + ((toTabRight - fromTabRight) * progress)),
getHeight());
invalidate();
}
/*
* position + positionOffset goes from 0 to 2 as we scroll from page 1 to 3.
* Normalized progress is relative to the the direction the page is being scrolled towards.
* For this, we maintain direction of scroll with a state, and the child view we are moving towards and away from.
*/
private void setScrollingData(int position, float positionOffset) {
if (position >= getChildCount() - 1) {
return;
}
final float currProgress = position + positionOffset;
if (mPrevProgress > currProgress) {
toTab = getChildAt(position);
fromTab = getChildAt(position + 1);
progress = 1 - positionOffset;
} else {
toTab = getChildAt(position + 1);
fromTab = getChildAt(position);
progress = positionOffset;
}
mPrevProgress = currProgress;
}
@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (mStrip != null) {
mStrip.draw(canvas);
}
}
@Override
public void onFocusChange(View v, boolean hasFocus) {
if (v == this && hasFocus && getChildCount() > 0) {
mSelectedView.requestFocus();
return;
}
if (!hasFocus) {
return;
}
int i = 0;
final int numTabs = getChildCount();
while (i < numTabs) {
View view = getChildAt(i);
if (view == v) {
view.requestFocus();
if (isShown()) {
// A view is focused so send an event to announce the menu strip state.
sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_FOCUSED);
}
break;
}
i++;
}
}
@Override
public void setOnTitleClickListener(HomePager.OnTitleClickListener onTitleClickListener) {
mOnTitleClickListener = onTitleClickListener;
}
private class ViewClickListener implements OnClickListener {
private final int mIndex;
public ViewClickListener(int index) {
mIndex = index;
}
@Override
public void onClick(View view) {
if (mOnTitleClickListener != null) {
mOnTitleClickListener.onTitleClicked(mIndex);
}
}
}
}