ScrollingTabContainerView.java revision da10fdd1400ecfd8d7f2e55651dd528d0614dfc5 
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 android.support.v7.internal.widget;
17
18import android.content.Context;
19import android.content.res.Configuration;
20import android.graphics.drawable.Drawable;
21import android.support.v7.app.ActionBar;
22import android.support.v7.appcompat.R;
23import android.support.v7.internal.view.ActionBarPolicy;
24import android.text.TextUtils.TruncateAt;
25import android.util.AttributeSet;
26import android.view.Gravity;
27import android.view.LayoutInflater;
28import android.view.View;
29import android.view.ViewGroup;
30import android.view.ViewParent;
31import android.widget.AdapterView;
32import android.widget.BaseAdapter;
33import android.widget.HorizontalScrollView;
34import android.widget.ImageView;
35import android.widget.LinearLayout;
36import android.widget.ListView;
37import android.widget.Spinner;
38import android.widget.TextView;
39
40/**
41 * This widget implements the dynamic action bar tab behavior that can change across different
42 * configurations or circumstances.
43 */
44public class ScrollingTabContainerView extends HorizontalScrollView
45        implements AdapterView.OnItemClickListener {
46
47    private static final String TAG = "ScrollingTabContainerView";
48    Runnable mTabSelector;
49    private TabClickListener mTabClickListener;
50
51    private LinearLayout mTabLayout;
52    private Spinner mTabSpinner;
53    private boolean mAllowCollapse;
54
55    private final LayoutInflater mInflater;
56
57    int mMaxTabWidth;
58    int mStackedTabMaxWidth;
59    private int mContentHeight;
60    private int mSelectedTabIndex;
61
62    public ScrollingTabContainerView(Context context) {
63        super(context);
64        mInflater = LayoutInflater.from(context);
65
66        setHorizontalScrollBarEnabled(false);
67
68        ActionBarPolicy abp = ActionBarPolicy.get(context);
69        setContentHeight(abp.getTabContainerHeight());
70        mStackedTabMaxWidth = abp.getStackedTabMaxWidth();
71
72        mTabLayout = (LinearLayout) mInflater.inflate(R.layout.action_bar_tabbar, this, false);
73        addView(mTabLayout, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
74                ViewGroup.LayoutParams.FILL_PARENT));
75    }
76
77    @Override
78    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
79        final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
80        final boolean lockedExpanded = widthMode == MeasureSpec.EXACTLY;
81        setFillViewport(lockedExpanded);
82
83        final int childCount = mTabLayout.getChildCount();
84        if (childCount > 1 &&
85                (widthMode == MeasureSpec.EXACTLY || widthMode == MeasureSpec.AT_MOST)) {
86            if (childCount > 2) {
87                mMaxTabWidth = (int) (MeasureSpec.getSize(widthMeasureSpec) * 0.4f);
88            } else {
89                mMaxTabWidth = MeasureSpec.getSize(widthMeasureSpec) / 2;
90            }
91            mMaxTabWidth = Math.min(mMaxTabWidth, mStackedTabMaxWidth);
92        } else {
93            mMaxTabWidth = -1;
94        }
95
96        heightMeasureSpec = MeasureSpec.makeMeasureSpec(mContentHeight, MeasureSpec.EXACTLY);
97
98        final boolean canCollapse = !lockedExpanded && mAllowCollapse;
99
100        if (canCollapse) {
101            // See if we should expand
102            mTabLayout.measure(MeasureSpec.UNSPECIFIED, heightMeasureSpec);
103            if (mTabLayout.getMeasuredWidth() > MeasureSpec.getSize(widthMeasureSpec)) {
104                performCollapse();
105            } else {
106                performExpand();
107            }
108        } else {
109            performExpand();
110        }
111
112        final int oldWidth = getMeasuredWidth();
113        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
114        final int newWidth = getMeasuredWidth();
115
116        if (lockedExpanded && oldWidth != newWidth) {
117            // Recenter the tab display if we're at a new (scrollable) size.
118            setTabSelected(mSelectedTabIndex);
119        }
120    }
121
122    /**
123     * Indicates whether this view is collapsed into a dropdown menu instead of traditional tabs.
124     *
125     * @return true if showing as a spinner
126     */
127    private boolean isCollapsed() {
128        return mTabSpinner != null && mTabSpinner.getParent() == this;
129    }
130
131    public void setAllowCollapse(boolean allowCollapse) {
132        mAllowCollapse = allowCollapse;
133    }
134
135    private void performCollapse() {
136        if (isCollapsed()) {
137            return;
138        }
139
140        if (mTabSpinner == null) {
141            mTabSpinner = createSpinner();
142        }
143        removeView(mTabLayout);
144        addView(mTabSpinner, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
145                ViewGroup.LayoutParams.FILL_PARENT));
146        if (mTabSpinner.getAdapter() == null) {
147            mTabSpinner.setAdapter(new TabAdapter());
148        }
149        if (mTabSelector != null) {
150            removeCallbacks(mTabSelector);
151            mTabSelector = null;
152        }
153        mTabSpinner.setSelection(mSelectedTabIndex);
154    }
155
156    private boolean performExpand() {
157        if (!isCollapsed()) {
158            return false;
159        }
160
161        removeView(mTabSpinner);
162        addView(mTabLayout, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
163                ViewGroup.LayoutParams.FILL_PARENT));
164        setTabSelected(mTabSpinner.getSelectedItemPosition());
165        return false;
166    }
167
168    public void setTabSelected(int position) {
169        mSelectedTabIndex = position;
170        final int tabCount = mTabLayout.getChildCount();
171        for (int i = 0; i < tabCount; i++) {
172            final View child = mTabLayout.getChildAt(i);
173            final boolean isSelected = i == position;
174            child.setSelected(isSelected);
175            if (isSelected) {
176                animateToTab(position);
177            }
178        }
179    }
180
181    public void setContentHeight(int contentHeight) {
182        mContentHeight = contentHeight;
183        requestLayout();
184    }
185
186    private Spinner createSpinner() {
187        final Spinner spinner = new Spinner(getContext(), null,
188                R.attr.actionDropDownStyle);
189        spinner.setLayoutParams(new LinearLayout.LayoutParams(
190                LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.FILL_PARENT));
191        spinner.setOnItemClickListener(this);
192        return spinner;
193    }
194
195    protected void onConfigurationChanged(Configuration newConfig) {
196        ActionBarPolicy abp = ActionBarPolicy.get(getContext());
197        // Action bar can change size on configuration changes.
198        // Reread the desired height from the theme-specified style.
199        setContentHeight(abp.getTabContainerHeight());
200        mStackedTabMaxWidth = abp.getStackedTabMaxWidth();
201    }
202
203    public void animateToTab(final int position) {
204        final View tabView = mTabLayout.getChildAt(position);
205        if (mTabSelector != null) {
206            removeCallbacks(mTabSelector);
207        }
208        mTabSelector = new Runnable() {
209            public void run() {
210                final int scrollPos = tabView.getLeft() - (getWidth() - tabView.getWidth()) / 2;
211                smoothScrollTo(scrollPos, 0);
212                mTabSelector = null;
213            }
214        };
215        post(mTabSelector);
216    }
217
218    @Override
219    public void onAttachedToWindow() {
220        super.onAttachedToWindow();
221        if (mTabSelector != null) {
222            // Re-post the selector we saved
223            post(mTabSelector);
224        }
225    }
226
227    @Override
228    public void onDetachedFromWindow() {
229        super.onDetachedFromWindow();
230        if (mTabSelector != null) {
231            removeCallbacks(mTabSelector);
232        }
233    }
234
235    private TabView createTabView(ActionBar.Tab tab, boolean forAdapter) {
236        final TabView tabView = (TabView) mInflater.inflate(R.layout.action_bar_tab, mTabLayout,
237                false);
238        tabView.attach(this, tab, forAdapter);
239
240        if (forAdapter) {
241            tabView.setBackgroundDrawable(null);
242            tabView.setLayoutParams(new ListView.LayoutParams(ListView.LayoutParams.FILL_PARENT,
243                    mContentHeight));
244        } else {
245            tabView.setFocusable(true);
246
247            if (mTabClickListener == null) {
248                mTabClickListener = new TabClickListener();
249            }
250            tabView.setOnClickListener(mTabClickListener);
251        }
252        return tabView;
253    }
254
255    public void addTab(ActionBar.Tab tab, boolean setSelected) {
256        TabView tabView = createTabView(tab, false);
257        mTabLayout.addView(tabView, new LinearLayout.LayoutParams(0,
258                LayoutParams.FILL_PARENT, 1));
259        if (mTabSpinner != null) {
260            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
261        }
262        if (setSelected) {
263            tabView.setSelected(true);
264        }
265        if (mAllowCollapse) {
266            requestLayout();
267        }
268    }
269
270    public void addTab(ActionBar.Tab tab, int position, boolean setSelected) {
271        final TabView tabView = createTabView(tab, false);
272        mTabLayout.addView(tabView, position, new LinearLayout.LayoutParams(
273                0, LayoutParams.FILL_PARENT, 1));
274        if (mTabSpinner != null) {
275            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
276        }
277        if (setSelected) {
278            tabView.setSelected(true);
279        }
280        if (mAllowCollapse) {
281            requestLayout();
282        }
283    }
284
285    public void updateTab(int position) {
286        ((TabView) mTabLayout.getChildAt(position)).update();
287        if (mTabSpinner != null) {
288            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
289        }
290        if (mAllowCollapse) {
291            requestLayout();
292        }
293    }
294
295    public void removeTabAt(int position) {
296        mTabLayout.removeViewAt(position);
297        if (mTabSpinner != null) {
298            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
299        }
300        if (mAllowCollapse) {
301            requestLayout();
302        }
303    }
304
305    public void removeAllTabs() {
306        mTabLayout.removeAllViews();
307        if (mTabSpinner != null) {
308            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
309        }
310        if (mAllowCollapse) {
311            requestLayout();
312        }
313    }
314
315    @Override
316    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
317        TabView tabView = (TabView) view;
318        tabView.getTab().select();
319    }
320
321    public static class TabView extends LinearLayout {
322
323        private ActionBar.Tab mTab;
324        private TextView mTextView;
325        private ImageView mIconView;
326        private View mCustomView;
327        private ScrollingTabContainerView mParent;
328
329        public TabView(Context context, AttributeSet attrs) {
330            super(context, attrs);
331        }
332
333        void attach(ScrollingTabContainerView parent, ActionBar.Tab tab, boolean forList) {
334            mParent = parent;
335            mTab = tab;
336
337            if (forList) {
338                setGravity(Gravity.LEFT | Gravity.CENTER_VERTICAL);
339            }
340
341            update();
342        }
343
344        public void bindTab(ActionBar.Tab tab) {
345            mTab = tab;
346            update();
347        }
348
349        @Override
350        public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
351            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
352
353            int maxTabWidth = mParent != null ? mParent.mMaxTabWidth : 0;
354
355            // Re-measure if we went beyond our maximum size.
356            if (maxTabWidth > 0 && getMeasuredWidth() > maxTabWidth) {
357                super.onMeasure(MeasureSpec.makeMeasureSpec(maxTabWidth, MeasureSpec.EXACTLY),
358                        heightMeasureSpec);
359            }
360        }
361
362        public void update() {
363            final ActionBar.Tab tab = mTab;
364            final View custom = tab.getCustomView();
365            if (custom != null) {
366                final ViewParent customParent = custom.getParent();
367                if (customParent != this) {
368                    if (customParent != null) {
369                        ((ViewGroup) customParent).removeView(custom);
370                    }
371                    addView(custom);
372                }
373                mCustomView = custom;
374                if (mTextView != null) {
375                    mTextView.setVisibility(GONE);
376                }
377                if (mIconView != null) {
378                    mIconView.setVisibility(GONE);
379                    mIconView.setImageDrawable(null);
380                }
381            } else {
382                if (mCustomView != null) {
383                    removeView(mCustomView);
384                    mCustomView = null;
385                }
386
387                final Drawable icon = tab.getIcon();
388                final CharSequence text = tab.getText();
389
390                if (icon != null) {
391                    if (mIconView == null) {
392                        ImageView iconView = new ImageView(getContext());
393                        LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT,
394                                LayoutParams.WRAP_CONTENT);
395                        lp.gravity = Gravity.CENTER_VERTICAL;
396                        iconView.setLayoutParams(lp);
397                        addView(iconView, 0);
398                        mIconView = iconView;
399                    }
400                    mIconView.setImageDrawable(icon);
401                    mIconView.setVisibility(VISIBLE);
402                } else if (mIconView != null) {
403                    mIconView.setVisibility(GONE);
404                    mIconView.setImageDrawable(null);
405                }
406
407                if (text != null) {
408                    if (mTextView == null) {
409                        TextView textView = new TextView(getContext(), null,
410                                R.attr.actionBarTabTextStyle);
411                        textView.setEllipsize(TruncateAt.END);
412                        LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT,
413                                LayoutParams.WRAP_CONTENT);
414                        lp.gravity = Gravity.CENTER_VERTICAL;
415                        textView.setLayoutParams(lp);
416                        addView(textView);
417                        mTextView = textView;
418                    }
419                    mTextView.setText(text);
420                    mTextView.setVisibility(VISIBLE);
421                } else if (mTextView != null) {
422                    mTextView.setVisibility(GONE);
423                    mTextView.setText(null);
424                }
425
426                if (mIconView != null) {
427                    mIconView.setContentDescription(tab.getContentDescription());
428                }
429            }
430        }
431
432        public ActionBar.Tab getTab() {
433            return mTab;
434        }
435    }
436
437    private class TabAdapter extends BaseAdapter {
438
439        @Override
440        public int getCount() {
441            return mTabLayout.getChildCount();
442        }
443
444        @Override
445        public Object getItem(int position) {
446            return ((TabView) mTabLayout.getChildAt(position)).getTab();
447        }
448
449        @Override
450        public long getItemId(int position) {
451            return position;
452        }
453
454        @Override
455        public View getView(int position, View convertView, ViewGroup parent) {
456            if (convertView == null) {
457                convertView = createTabView((ActionBar.Tab) getItem(position), true);
458            } else {
459                ((TabView) convertView).bindTab((ActionBar.Tab) getItem(position));
460            }
461            return convertView;
462        }
463    }
464
465    private class TabClickListener implements OnClickListener {
466
467        public void onClick(View view) {
468            TabView tabView = (TabView) view;
469            tabView.getTab().select();
470            final int tabCount = mTabLayout.getChildCount();
471            for (int i = 0; i < tabCount; i++) {
472                final View child = mTabLayout.getChildAt(i);
473                child.setSelected(child == view);
474            }
475        }
476    }
477
478}
479
480