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.BaseAdapter;
32import android.widget.HorizontalScrollView;
33import android.widget.ImageView;
34import android.widget.LinearLayout;
35import android.widget.ListView;
36import android.widget.TextView;
37
38/**
39 * This widget implements the dynamic action bar tab behavior that can change across different
40 * configurations or circumstances.
41 *
42 * @hide
43 */
44public class ScrollingTabContainerView extends HorizontalScrollView
45        implements AdapterViewICS.OnItemClickListener {
46
47    private static final String TAG = "ScrollingTabContainerView";
48    Runnable mTabSelector;
49    private TabClickListener mTabClickListener;
50
51    private LinearLayout mTabLayout;
52    private SpinnerICS 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.abc_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        if (mTabSpinner != null && position >= 0) {
180            mTabSpinner.setSelection(position);
181        }
182    }
183
184    public void setContentHeight(int contentHeight) {
185        mContentHeight = contentHeight;
186        requestLayout();
187    }
188
189    private SpinnerICS createSpinner() {
190        final SpinnerICS spinner = new SpinnerICS(getContext(), null,
191                R.attr.actionDropDownStyle);
192        spinner.setLayoutParams(new LinearLayout.LayoutParams(
193                LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.FILL_PARENT));
194        spinner.setOnItemClickListenerInt(this);
195        return spinner;
196    }
197
198    protected void onConfigurationChanged(Configuration newConfig) {
199        ActionBarPolicy abp = ActionBarPolicy.get(getContext());
200        // Action bar can change size on configuration changes.
201        // Reread the desired height from the theme-specified style.
202        setContentHeight(abp.getTabContainerHeight());
203        mStackedTabMaxWidth = abp.getStackedTabMaxWidth();
204    }
205
206    public void animateToTab(final int position) {
207        final View tabView = mTabLayout.getChildAt(position);
208        if (mTabSelector != null) {
209            removeCallbacks(mTabSelector);
210        }
211        mTabSelector = new Runnable() {
212            public void run() {
213                final int scrollPos = tabView.getLeft() - (getWidth() - tabView.getWidth()) / 2;
214                smoothScrollTo(scrollPos, 0);
215                mTabSelector = null;
216            }
217        };
218        post(mTabSelector);
219    }
220
221    @Override
222    public void onAttachedToWindow() {
223        super.onAttachedToWindow();
224        if (mTabSelector != null) {
225            // Re-post the selector we saved
226            post(mTabSelector);
227        }
228    }
229
230    @Override
231    public void onDetachedFromWindow() {
232        super.onDetachedFromWindow();
233        if (mTabSelector != null) {
234            removeCallbacks(mTabSelector);
235        }
236    }
237
238    private TabView createTabView(ActionBar.Tab tab, boolean forAdapter) {
239        final TabView tabView = (TabView) mInflater.inflate(R.layout.abc_action_bar_tab, mTabLayout,
240                false);
241        tabView.attach(this, tab, forAdapter);
242
243        if (forAdapter) {
244            tabView.setBackgroundDrawable(null);
245            tabView.setLayoutParams(new ListView.LayoutParams(ListView.LayoutParams.FILL_PARENT,
246                    mContentHeight));
247        } else {
248            tabView.setFocusable(true);
249
250            if (mTabClickListener == null) {
251                mTabClickListener = new TabClickListener();
252            }
253            tabView.setOnClickListener(mTabClickListener);
254        }
255        return tabView;
256    }
257
258    public void addTab(ActionBar.Tab tab, boolean setSelected) {
259        TabView tabView = createTabView(tab, false);
260        mTabLayout.addView(tabView, new LinearLayout.LayoutParams(0,
261                LayoutParams.FILL_PARENT, 1));
262        if (mTabSpinner != null) {
263            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
264        }
265        if (setSelected) {
266            tabView.setSelected(true);
267        }
268        if (mAllowCollapse) {
269            requestLayout();
270        }
271    }
272
273    public void addTab(ActionBar.Tab tab, int position, boolean setSelected) {
274        final TabView tabView = createTabView(tab, false);
275        mTabLayout.addView(tabView, position, new LinearLayout.LayoutParams(
276                0, LayoutParams.FILL_PARENT, 1));
277        if (mTabSpinner != null) {
278            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
279        }
280        if (setSelected) {
281            tabView.setSelected(true);
282        }
283        if (mAllowCollapse) {
284            requestLayout();
285        }
286    }
287
288    public void updateTab(int position) {
289        ((TabView) mTabLayout.getChildAt(position)).update();
290        if (mTabSpinner != null) {
291            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
292        }
293        if (mAllowCollapse) {
294            requestLayout();
295        }
296    }
297
298    public void removeTabAt(int position) {
299        mTabLayout.removeViewAt(position);
300        if (mTabSpinner != null) {
301            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
302        }
303        if (mAllowCollapse) {
304            requestLayout();
305        }
306    }
307
308    public void removeAllTabs() {
309        mTabLayout.removeAllViews();
310        if (mTabSpinner != null) {
311            ((TabAdapter) mTabSpinner.getAdapter()).notifyDataSetChanged();
312        }
313        if (mAllowCollapse) {
314            requestLayout();
315        }
316    }
317
318    @Override
319    public void onItemClick(AdapterViewICS<?> parent, View view, int position, long id) {
320        TabView tabView = (TabView) view;
321        tabView.getTab().select();
322    }
323
324    /**
325     * @hide
326     */
327    public static class TabView extends LinearLayout {
328
329        private ActionBar.Tab mTab;
330        private TextView mTextView;
331        private ImageView mIconView;
332        private View mCustomView;
333        private ScrollingTabContainerView mParent;
334
335        public TabView(Context context, AttributeSet attrs) {
336            super(context, attrs);
337        }
338
339        void attach(ScrollingTabContainerView parent, ActionBar.Tab tab, boolean forList) {
340            mParent = parent;
341            mTab = tab;
342
343            if (forList) {
344                setGravity(Gravity.LEFT | Gravity.CENTER_VERTICAL);
345            }
346
347            update();
348        }
349
350        public void bindTab(ActionBar.Tab tab) {
351            mTab = tab;
352            update();
353        }
354
355        @Override
356        public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
357            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
358
359            int maxTabWidth = mParent != null ? mParent.mMaxTabWidth : 0;
360
361            // Re-measure if we went beyond our maximum size.
362            if (maxTabWidth > 0 && getMeasuredWidth() > maxTabWidth) {
363                super.onMeasure(MeasureSpec.makeMeasureSpec(maxTabWidth, MeasureSpec.EXACTLY),
364                        heightMeasureSpec);
365            }
366        }
367
368        public void update() {
369            final ActionBar.Tab tab = mTab;
370            final View custom = tab.getCustomView();
371            if (custom != null) {
372                final ViewParent customParent = custom.getParent();
373                if (customParent != this) {
374                    if (customParent != null) {
375                        ((ViewGroup) customParent).removeView(custom);
376                    }
377                    addView(custom);
378                }
379                mCustomView = custom;
380                if (mTextView != null) {
381                    mTextView.setVisibility(GONE);
382                }
383                if (mIconView != null) {
384                    mIconView.setVisibility(GONE);
385                    mIconView.setImageDrawable(null);
386                }
387            } else {
388                if (mCustomView != null) {
389                    removeView(mCustomView);
390                    mCustomView = null;
391                }
392
393                final Drawable icon = tab.getIcon();
394                final CharSequence text = tab.getText();
395
396                if (icon != null) {
397                    if (mIconView == null) {
398                        ImageView iconView = new ImageView(getContext());
399                        LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT,
400                                LayoutParams.WRAP_CONTENT);
401                        lp.gravity = Gravity.CENTER_VERTICAL;
402                        iconView.setLayoutParams(lp);
403                        addView(iconView, 0);
404                        mIconView = iconView;
405                    }
406                    mIconView.setImageDrawable(icon);
407                    mIconView.setVisibility(VISIBLE);
408                } else if (mIconView != null) {
409                    mIconView.setVisibility(GONE);
410                    mIconView.setImageDrawable(null);
411                }
412
413                if (text != null) {
414                    if (mTextView == null) {
415                        TextView textView = new CompatTextView(getContext(), null,
416                                R.attr.actionBarTabTextStyle);
417                        textView.setEllipsize(TruncateAt.END);
418                        LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT,
419                                LayoutParams.WRAP_CONTENT);
420                        lp.gravity = Gravity.CENTER_VERTICAL;
421                        textView.setLayoutParams(lp);
422                        addView(textView);
423                        mTextView = textView;
424                    }
425                    mTextView.setText(text);
426                    mTextView.setVisibility(VISIBLE);
427                } else if (mTextView != null) {
428                    mTextView.setVisibility(GONE);
429                    mTextView.setText(null);
430                }
431
432                if (mIconView != null) {
433                    mIconView.setContentDescription(tab.getContentDescription());
434                }
435            }
436        }
437
438        public ActionBar.Tab getTab() {
439            return mTab;
440        }
441    }
442
443    private class TabAdapter extends BaseAdapter {
444
445        @Override
446        public int getCount() {
447            return mTabLayout.getChildCount();
448        }
449
450        @Override
451        public Object getItem(int position) {
452            return ((TabView) mTabLayout.getChildAt(position)).getTab();
453        }
454
455        @Override
456        public long getItemId(int position) {
457            return position;
458        }
459
460        @Override
461        public View getView(int position, View convertView, ViewGroup parent) {
462            if (convertView == null) {
463                convertView = createTabView((ActionBar.Tab) getItem(position), true);
464            } else {
465                ((TabView) convertView).bindTab((ActionBar.Tab) getItem(position));
466            }
467            return convertView;
468        }
469    }
470
471    private class TabClickListener implements OnClickListener {
472
473        public void onClick(View view) {
474            TabView tabView = (TabView) view;
475            tabView.getTab().select();
476            final int tabCount = mTabLayout.getChildCount();
477            for (int i = 0; i < tabCount; i++) {
478                final View child = mTabLayout.getChildAt(i);
479                child.setSelected(child == view);
480            }
481        }
482    }
483
484}
485
486