1/*
2 * Copyright (C) 2011 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 */
16package com.android.internal.widget;
17
18import com.android.internal.view.ActionBarPolicy;
19
20import android.animation.Animator;
21import android.animation.ObjectAnimator;
22import android.animation.TimeInterpolator;
23import android.app.ActionBar;
24import android.content.Context;
25import android.content.res.Configuration;
26import android.graphics.Rect;
27import android.graphics.drawable.Drawable;
28import android.text.TextUtils;
29import android.text.TextUtils.TruncateAt;
30import android.view.Gravity;
31import android.view.View;
32import android.view.ViewGroup;
33import android.view.ViewParent;
34import android.view.accessibility.AccessibilityEvent;
35import android.view.accessibility.AccessibilityNodeInfo;
36import android.view.animation.DecelerateInterpolator;
37import android.widget.AdapterView;
38import android.widget.BaseAdapter;
39import android.widget.HorizontalScrollView;
40import android.widget.ImageView;
41import android.widget.LinearLayout;
42import android.widget.ListView;
43import android.widget.Spinner;
44import android.widget.TextView;
45import android.widget.Toast;
46
47/**
48 * This widget implements the dynamic action bar tab behavior that can change
49 * across different configurations or circumstances.
50 */
51public class ScrollingTabContainerView extends HorizontalScrollView
52        implements AdapterView.OnItemClickListener {
53    private static final String TAG = "ScrollingTabContainerView";
54    Runnable mTabSelector;
55    private TabClickListener mTabClickListener;
56
57    private LinearLayout mTabLayout;
58    private Spinner mTabSpinner;
59    private boolean mAllowCollapse;
60
61    int mMaxTabWidth;
62    int mStackedTabMaxWidth;
63    private int mContentHeight;
64    private int mSelectedTabIndex;
65
66    protected Animator mVisibilityAnim;
67    protected final VisibilityAnimListener mVisAnimListener = new VisibilityAnimListener();
68
69    private static final TimeInterpolator sAlphaInterpolator = new DecelerateInterpolator();
70
71    private static final int FADE_DURATION = 200;
72
73    public ScrollingTabContainerView(Context context) {
74        super(context);
75        setHorizontalScrollBarEnabled(false);
76
77        ActionBarPolicy abp = ActionBarPolicy.get(context);
78        setContentHeight(abp.getTabContainerHeight());
79        mStackedTabMaxWidth = abp.getStackedTabMaxWidth();
80
81        mTabLayout = createTabLayout();
82        addView(mTabLayout, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
83                ViewGroup.LayoutParams.MATCH_PARENT));
84    }
85
86    @Override
87    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
88        final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
89        final boolean lockedExpanded = widthMode == MeasureSpec.EXACTLY;
90        setFillViewport(lockedExpanded);
91
92        final int childCount = mTabLayout.getChildCount();
93        if (childCount > 1 &&
94                (widthMode == MeasureSpec.EXACTLY || widthMode == MeasureSpec.AT_MOST)) {
95            if (childCount > 2) {
96                mMaxTabWidth = (int) (MeasureSpec.getSize(widthMeasureSpec) * 0.4f);
97            } else {
98                mMaxTabWidth = MeasureSpec.getSize(widthMeasureSpec) / 2;
99            }
100            mMaxTabWidth = Math.min(mMaxTabWidth, mStackedTabMaxWidth);
101        } else {
102            mMaxTabWidth = -1;
103        }
104
105        heightMeasureSpec = MeasureSpec.makeMeasureSpec(mContentHeight, MeasureSpec.EXACTLY);
106
107        final boolean canCollapse = !lockedExpanded && mAllowCollapse;
108
109        if (canCollapse) {
110            // See if we should expand
111            mTabLayout.measure(MeasureSpec.UNSPECIFIED, heightMeasureSpec);
112            if (mTabLayout.getMeasuredWidth() > MeasureSpec.getSize(widthMeasureSpec)) {
113                performCollapse();
114            } else {
115                performExpand();
116            }
117        } else {
118            performExpand();
119        }
120
121        final int oldWidth = getMeasuredWidth();
122        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
123        final int newWidth = getMeasuredWidth();
124
125        if (lockedExpanded && oldWidth != newWidth) {
126            // Recenter the tab display if we're at a new (scrollable) size.
127            setTabSelected(mSelectedTabIndex);
128        }
129    }
130
131    /**
132     * Indicates whether this view is collapsed into a dropdown menu instead
133     * of traditional tabs.
134     * @return true if showing as a spinner
135     */
136    private boolean isCollapsed() {
137        return mTabSpinner != null && mTabSpinner.getParent() == this;
138    }
139
140    public void setAllowCollapse(boolean allowCollapse) {
141        mAllowCollapse = allowCollapse;
142    }
143
144    private void performCollapse() {
145        if (isCollapsed()) return;
146
147        if (mTabSpinner == null) {
148            mTabSpinner = createSpinner();
149        }
150        removeView(mTabLayout);
151        addView(mTabSpinner, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
152                ViewGroup.LayoutParams.MATCH_PARENT));
153        if (mTabSpinner.getAdapter() == null) {
154            mTabSpinner.setAdapter(new TabAdapter());
155        }
156        if (mTabSelector != null) {
157            removeCallbacks(mTabSelector);
158            mTabSelector = null;
159        }
160        mTabSpinner.setSelection(mSelectedTabIndex);
161    }
162
163    private boolean performExpand() {
164        if (!isCollapsed()) return false;
165
166        removeView(mTabSpinner);
167        addView(mTabLayout, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
168                ViewGroup.LayoutParams.MATCH_PARENT));
169        setTabSelected(mTabSpinner.getSelectedItemPosition());
170        return false;
171    }
172
173    public void setTabSelected(int position) {
174        mSelectedTabIndex = position;
175        final int tabCount = mTabLayout.getChildCount();
176        for (int i = 0; i < tabCount; i++) {
177            final View child = mTabLayout.getChildAt(i);
178            final boolean isSelected = i == position;
179            child.setSelected(isSelected);
180            if (isSelected) {
181                animateToTab(position);
182            }
183        }
184        if (mTabSpinner != null && position >= 0) {
185            mTabSpinner.setSelection(position);
186        }
187    }
188
189    public void setContentHeight(int contentHeight) {
190        mContentHeight = contentHeight;
191        requestLayout();
192    }
193
194    private LinearLayout createTabLayout() {
195        final LinearLayout tabLayout = new LinearLayout(getContext(), null,
196                com.android.internal.R.attr.actionBarTabBarStyle);
197        tabLayout.setMeasureWithLargestChildEnabled(true);
198        tabLayout.setGravity(Gravity.CENTER);
199        tabLayout.setLayoutParams(new LinearLayout.LayoutParams(
200                LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.MATCH_PARENT));
201        return tabLayout;
202    }
203
204    private Spinner createSpinner() {
205        final Spinner spinner = new Spinner(getContext(), null,
206                com.android.internal.R.attr.actionDropDownStyle);
207        spinner.setLayoutParams(new LinearLayout.LayoutParams(
208                LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.MATCH_PARENT));
209        spinner.setOnItemClickListenerInt(this);
210        return spinner;
211    }
212
213    @Override
214    protected void onConfigurationChanged(Configuration newConfig) {
215        super.onConfigurationChanged(newConfig);
216
217        ActionBarPolicy abp = ActionBarPolicy.get(getContext());
218        // Action bar can change size on configuration changes.
219        // Reread the desired height from the theme-specified style.
220        setContentHeight(abp.getTabContainerHeight());
221        mStackedTabMaxWidth = abp.getStackedTabMaxWidth();
222    }
223
224    public void animateToVisibility(int visibility) {
225        if (mVisibilityAnim != null) {
226            mVisibilityAnim.cancel();
227        }
228        if (visibility == VISIBLE) {
229            if (getVisibility() != VISIBLE) {
230                setAlpha(0);
231            }
232            ObjectAnimator anim = ObjectAnimator.ofFloat(this, "alpha", 1);
233            anim.setDuration(FADE_DURATION);
234            anim.setInterpolator(sAlphaInterpolator);
235
236            anim.addListener(mVisAnimListener.withFinalVisibility(visibility));
237            anim.start();
238        } else {
239            ObjectAnimator anim = ObjectAnimator.ofFloat(this, "alpha", 0);
240            anim.setDuration(FADE_DURATION);
241            anim.setInterpolator(sAlphaInterpolator);
242
243            anim.addListener(mVisAnimListener.withFinalVisibility(visibility));
244            anim.start();
245        }
246    }
247
248    public void animateToTab(final int position) {
249        final View tabView = mTabLayout.getChildAt(position);
250        if (mTabSelector != null) {
251            removeCallbacks(mTabSelector);
252        }
253        mTabSelector = new Runnable() {
254            public void run() {
255                final int scrollPos = tabView.getLeft() - (getWidth() - tabView.getWidth()) / 2;
256                smoothScrollTo(scrollPos, 0);
257                mTabSelector = null;
258            }
259        };
260        post(mTabSelector);
261    }
262
263    @Override
264    public void onAttachedToWindow() {
265        super.onAttachedToWindow();
266        if (mTabSelector != null) {
267            // Re-post the selector we saved
268            post(mTabSelector);
269        }
270    }
271
272    @Override
273    public void onDetachedFromWindow() {
274        super.onDetachedFromWindow();
275        if (mTabSelector != null) {
276            removeCallbacks(mTabSelector);
277        }
278    }
279
280    private TabView createTabView(ActionBar.Tab tab, boolean forAdapter) {
281        final TabView tabView = new TabView(getContext(), tab, forAdapter);
282        if (forAdapter) {
283            tabView.setBackgroundDrawable(null);
284            tabView.setLayoutParams(new ListView.LayoutParams(ListView.LayoutParams.MATCH_PARENT,
285                    mContentHeight));
286        } else {
287            tabView.setFocusable(true);
288
289            if (mTabClickListener == null) {
290                mTabClickListener = new TabClickListener();
291            }
292            tabView.setOnClickListener(mTabClickListener);
293        }
294        return tabView;
295    }
296
297    public void addTab(ActionBar.Tab tab, boolean setSelected) {
298        TabView tabView = createTabView(tab, false);
299        mTabLayout.addView(tabView, new LinearLayout.LayoutParams(0,
300                LayoutParams.MATCH_PARENT, 1));
301        if (mTabSpinner != null) {
302            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
303        }
304        if (setSelected) {
305            tabView.setSelected(true);
306        }
307        if (mAllowCollapse) {
308            requestLayout();
309        }
310    }
311
312    public void addTab(ActionBar.Tab tab, int position, boolean setSelected) {
313        final TabView tabView = createTabView(tab, false);
314        mTabLayout.addView(tabView, position, new LinearLayout.LayoutParams(
315                0, LayoutParams.MATCH_PARENT, 1));
316        if (mTabSpinner != null) {
317            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
318        }
319        if (setSelected) {
320            tabView.setSelected(true);
321        }
322        if (mAllowCollapse) {
323            requestLayout();
324        }
325    }
326
327    public void updateTab(int position) {
328        ((TabView) mTabLayout.getChildAt(position)).update();
329        if (mTabSpinner != null) {
330            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
331        }
332        if (mAllowCollapse) {
333            requestLayout();
334        }
335    }
336
337    public void removeTabAt(int position) {
338        mTabLayout.removeViewAt(position);
339        if (mTabSpinner != null) {
340            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
341        }
342        if (mAllowCollapse) {
343            requestLayout();
344        }
345    }
346
347    public void removeAllTabs() {
348        mTabLayout.removeAllViews();
349        if (mTabSpinner != null) {
350            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
351        }
352        if (mAllowCollapse) {
353            requestLayout();
354        }
355    }
356
357    @Override
358    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
359        TabView tabView = (TabView) view;
360        tabView.getTab().select();
361    }
362
363    private class TabView extends LinearLayout implements OnLongClickListener {
364        private ActionBar.Tab mTab;
365        private TextView mTextView;
366        private ImageView mIconView;
367        private View mCustomView;
368
369        public TabView(Context context, ActionBar.Tab tab, boolean forList) {
370            super(context, null, com.android.internal.R.attr.actionBarTabStyle);
371            mTab = tab;
372
373            if (forList) {
374                setGravity(Gravity.START | Gravity.CENTER_VERTICAL);
375            }
376
377            update();
378        }
379
380        public void bindTab(ActionBar.Tab tab) {
381            mTab = tab;
382            update();
383        }
384
385        @Override
386        public void setSelected(boolean selected) {
387            final boolean changed = (isSelected() != selected);
388            super.setSelected(selected);
389            if (changed && selected) {
390                sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_SELECTED);
391            }
392        }
393
394        @Override
395        public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
396            super.onInitializeAccessibilityEvent(event);
397            // This view masquerades as an action bar tab.
398            event.setClassName(ActionBar.Tab.class.getName());
399        }
400
401        @Override
402        public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
403            super.onInitializeAccessibilityNodeInfo(info);
404            // This view masquerades as an action bar tab.
405            info.setClassName(ActionBar.Tab.class.getName());
406        }
407
408        @Override
409        public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
410            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
411
412            // Re-measure if we went beyond our maximum size.
413            if (mMaxTabWidth > 0 && getMeasuredWidth() > mMaxTabWidth) {
414                super.onMeasure(MeasureSpec.makeMeasureSpec(mMaxTabWidth, MeasureSpec.EXACTLY),
415                        heightMeasureSpec);
416            }
417        }
418
419        public void update() {
420            final ActionBar.Tab tab = mTab;
421            final View custom = tab.getCustomView();
422            if (custom != null) {
423                final ViewParent customParent = custom.getParent();
424                if (customParent != this) {
425                    if (customParent != null) ((ViewGroup) customParent).removeView(custom);
426                    addView(custom);
427                }
428                mCustomView = custom;
429                if (mTextView != null) mTextView.setVisibility(GONE);
430                if (mIconView != null) {
431                    mIconView.setVisibility(GONE);
432                    mIconView.setImageDrawable(null);
433                }
434            } else {
435                if (mCustomView != null) {
436                    removeView(mCustomView);
437                    mCustomView = null;
438                }
439
440                final Drawable icon = tab.getIcon();
441                final CharSequence text = tab.getText();
442
443                if (icon != null) {
444                    if (mIconView == null) {
445                        ImageView iconView = new ImageView(getContext());
446                        LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT,
447                                LayoutParams.WRAP_CONTENT);
448                        lp.gravity = Gravity.CENTER_VERTICAL;
449                        iconView.setLayoutParams(lp);
450                        addView(iconView, 0);
451                        mIconView = iconView;
452                    }
453                    mIconView.setImageDrawable(icon);
454                    mIconView.setVisibility(VISIBLE);
455                } else if (mIconView != null) {
456                    mIconView.setVisibility(GONE);
457                    mIconView.setImageDrawable(null);
458                }
459
460                final boolean hasText = !TextUtils.isEmpty(text);
461                if (hasText) {
462                    if (mTextView == null) {
463                        TextView textView = new TextView(getContext(), null,
464                                com.android.internal.R.attr.actionBarTabTextStyle);
465                        textView.setEllipsize(TruncateAt.END);
466                        LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT,
467                                LayoutParams.WRAP_CONTENT);
468                        lp.gravity = Gravity.CENTER_VERTICAL;
469                        textView.setLayoutParams(lp);
470                        addView(textView);
471                        mTextView = textView;
472                    }
473                    mTextView.setText(text);
474                    mTextView.setVisibility(VISIBLE);
475                } else if (mTextView != null) {
476                    mTextView.setVisibility(GONE);
477                    mTextView.setText(null);
478                }
479
480                if (mIconView != null) {
481                    mIconView.setContentDescription(tab.getContentDescription());
482                }
483
484                if (!hasText && !TextUtils.isEmpty(tab.getContentDescription())) {
485                    setOnLongClickListener(this);
486                } else {
487                    setOnLongClickListener(null);
488                    setLongClickable(false);
489                }
490            }
491        }
492
493        public boolean onLongClick(View v) {
494            final int[] screenPos = new int[2];
495            getLocationOnScreen(screenPos);
496
497            final Context context = getContext();
498            final int width = getWidth();
499            final int height = getHeight();
500            final int screenWidth = context.getResources().getDisplayMetrics().widthPixels;
501
502            Toast cheatSheet = Toast.makeText(context, mTab.getContentDescription(),
503                    Toast.LENGTH_SHORT);
504            // Show under the tab
505            cheatSheet.setGravity(Gravity.TOP | Gravity.CENTER_HORIZONTAL,
506                    (screenPos[0] + width / 2) - screenWidth / 2, height);
507
508            cheatSheet.show();
509            return true;
510        }
511
512        public ActionBar.Tab getTab() {
513            return mTab;
514        }
515    }
516
517    private class TabAdapter extends BaseAdapter {
518        @Override
519        public int getCount() {
520            return mTabLayout.getChildCount();
521        }
522
523        @Override
524        public Object getItem(int position) {
525            return ((TabView) mTabLayout.getChildAt(position)).getTab();
526        }
527
528        @Override
529        public long getItemId(int position) {
530            return position;
531        }
532
533        @Override
534        public View getView(int position, View convertView, ViewGroup parent) {
535            if (convertView == null) {
536                convertView = createTabView((ActionBar.Tab) getItem(position), true);
537            } else {
538                ((TabView) convertView).bindTab((ActionBar.Tab) getItem(position));
539            }
540            return convertView;
541        }
542    }
543
544    private class TabClickListener implements OnClickListener {
545        public void onClick(View view) {
546            TabView tabView = (TabView) view;
547            tabView.getTab().select();
548            final int tabCount = mTabLayout.getChildCount();
549            for (int i = 0; i < tabCount; i++) {
550                final View child = mTabLayout.getChildAt(i);
551                child.setSelected(child == view);
552            }
553        }
554    }
555
556    protected class VisibilityAnimListener implements Animator.AnimatorListener {
557        private boolean mCanceled = false;
558        private int mFinalVisibility;
559
560        public VisibilityAnimListener withFinalVisibility(int visibility) {
561            mFinalVisibility = visibility;
562            return this;
563        }
564
565        @Override
566        public void onAnimationStart(Animator animation) {
567            setVisibility(VISIBLE);
568            mVisibilityAnim = animation;
569            mCanceled = false;
570        }
571
572        @Override
573        public void onAnimationEnd(Animator animation) {
574            if (mCanceled) return;
575
576            mVisibilityAnim = null;
577            setVisibility(mFinalVisibility);
578        }
579
580        @Override
581        public void onAnimationCancel(Animator animation) {
582            mCanceled = true;
583        }
584
585        @Override
586        public void onAnimationRepeat(Animator animation) {
587        }
588    }
589}
590