michael@0: /* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: package org.mozilla.gecko.home;
michael@0: 
michael@0: import org.mozilla.gecko.R;
michael@0: 
michael@0: import android.content.Context;
michael@0: import android.content.res.TypedArray;
michael@0: import android.graphics.Canvas;
michael@0: import android.graphics.drawable.Drawable;
michael@0: import android.util.AttributeSet;
michael@0: import android.view.LayoutInflater;
michael@0: import android.view.View;
michael@0: import android.view.ViewTreeObserver;
michael@0: import android.view.accessibility.AccessibilityEvent;
michael@0: import android.widget.HorizontalScrollView;
michael@0: import android.widget.LinearLayout;
michael@0: import android.widget.TextView;
michael@0: 
michael@0: /**
michael@0:  * {@code TabMenuStrip} is the view used to display {@code HomePager} tabs
michael@0:  * on tablets. See {@code TabMenuStripLayout} for details about how the
michael@0:  * tabs are created and updated.
michael@0:  */
michael@0: public class TabMenuStrip extends HorizontalScrollView
michael@0:                           implements HomePager.Decor {
michael@0: 
michael@0:     // Offset between the selected tab title and the edge of the screen,
michael@0:     // except for the first and last tab in the tab strip.
michael@0:     private static final int TITLE_OFFSET_DIPS = 24;
michael@0: 
michael@0:     private final int titleOffset;
michael@0:     private final TabMenuStripLayout layout;
michael@0: 
michael@0:     public TabMenuStrip(Context context, AttributeSet attrs) {
michael@0:         super(context, attrs);
michael@0: 
michael@0:         // Disable the scroll bar.
michael@0:         setHorizontalScrollBarEnabled(false);
michael@0: 
michael@0:         titleOffset = (int) (TITLE_OFFSET_DIPS * getResources().getDisplayMetrics().density);
michael@0: 
michael@0:         layout = new TabMenuStripLayout(context, attrs);
michael@0:         addView(layout, LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public void onAddPagerView(String title) {
michael@0:         layout.onAddPagerView(title);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public void removeAllPagerViews() {
michael@0:         layout.removeAllViews();
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public void onPageSelected(final int position) {
michael@0:         layout.onPageSelected(position);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
michael@0:         layout.onPageScrolled(position, positionOffset, positionOffsetPixels);
michael@0: 
michael@0:         final View selectedTitle = layout.getChildAt(position);
michael@0:         if (selectedTitle == null) {
michael@0:             return;
michael@0:         }
michael@0: 
michael@0:         final int selectedTitleOffset = (int) (positionOffset * selectedTitle.getWidth());
michael@0: 
michael@0:         int titleLeft = selectedTitle.getLeft() + selectedTitleOffset;
michael@0:         if (position > 0) {
michael@0:             titleLeft -= titleOffset;
michael@0:         }
michael@0: 
michael@0:         int titleRight = selectedTitle.getRight() + selectedTitleOffset;
michael@0:         if (position < layout.getChildCount() - 1) {
michael@0:             titleRight += titleOffset;
michael@0:         }
michael@0: 
michael@0:         final int scrollX = getScrollX();
michael@0:         if (titleLeft < scrollX) {
michael@0:             // Tab strip overflows to the left.
michael@0:             scrollTo(titleLeft, 0);
michael@0:         } else if (titleRight > scrollX + getWidth()) {
michael@0:             // Tab strip overflows to the right.
michael@0:             scrollTo(titleRight - getWidth(), 0);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public void setOnTitleClickListener(HomePager.OnTitleClickListener onTitleClickListener) {
michael@0:         layout.setOnTitleClickListener(onTitleClickListener);
michael@0:     }
michael@0: }