1/*
2 * Copyright (C) 2008 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 */
16
17package android.util;
18
19import com.google.android.collect.Lists;
20
21import android.app.Activity;
22import android.content.Context;
23import android.os.Bundle;
24import android.view.View;
25import android.view.ViewGroup;
26import android.view.Window;
27import android.widget.Button;
28import android.widget.LinearLayout;
29import android.widget.ScrollView;
30import android.widget.TextView;
31
32import java.util.List;
33
34/**
35 * Utility base class for creating scroll view scenarios, allowing you to add
36 * a series of different kinds of views arranged vertically, taking up a
37 * specified amount of the screen height.
38 */
39public abstract class ScrollViewScenario extends Activity {
40
41    /**
42     * Holds content of scroll view
43     */
44    private LinearLayout mLinearLayout;
45
46    /**
47     * The actual scroll view
48     */
49    private ScrollView mScrollView;
50
51
52    /**
53     * What we need of each view that the user wants: the view, and the ratio
54     * to the screen height for its desired height.
55     */
56    private interface ViewFactory {
57        View create(final Context context);
58
59        float getHeightRatio();
60    }
61
62    /**
63     * Partially implement ViewFactory given a height ratio.
64     * A negative height ratio means that WRAP_CONTENT will be used as height
65     */
66    private static abstract class ViewFactoryBase implements ViewFactory {
67
68        private float mHeightRatio;
69
70        @SuppressWarnings({"UnusedDeclaration"})
71        private ViewFactoryBase() {throw new UnsupportedOperationException("don't call this!");}
72
73        protected ViewFactoryBase(float heightRatio) {
74            mHeightRatio = heightRatio;
75        }
76
77        public float getHeightRatio() {
78            return mHeightRatio;
79        }
80    }
81
82    /**
83     * Builder for selecting the views to be vertically arranged in the scroll
84     * view.
85     */
86    @SuppressWarnings({"JavaDoc"})
87    public static class Params {
88
89        List<ViewFactory> mViewFactories = Lists.newArrayList();
90
91        int mTopPadding = 0;
92        int mBottomPadding = 0;
93
94        /**
95         * Add a text view.
96         * @param text The text of the text view.
97         * @param heightRatio The view's height will be this * the screen height.
98         */
99        public Params addTextView(final String text, float heightRatio) {
100            mViewFactories.add(new ViewFactoryBase(heightRatio) {
101                public View create(final Context context) {
102                    final TextView tv = new TextView(context);
103                    tv.setText(text);
104                    return tv;
105                }
106            });
107            return this;
108        }
109
110        /**
111         * Add multiple text views.
112         * @param numViews the number of views to add.
113         * @param textPrefix The text to prepend to each text view.
114         * @param heightRatio The view's height will be this * the screen height.
115         */
116        public Params addTextViews(int numViews, String textPrefix, float heightRatio) {
117            for (int i = 0; i < numViews; i++) {
118                addTextView(textPrefix + i, heightRatio);
119            }
120            return this;
121        }
122
123        /**
124         * Add a button.
125         * @param text The text of the button.
126         * @param heightRatio The view's height will be this * the screen height.
127         */
128        public Params addButton(final String text, float heightRatio) {
129            mViewFactories.add(new ViewFactoryBase(heightRatio) {
130                public View create(final Context context) {
131                    final Button button = new Button(context);
132                    button.setText(text);
133                    return button;
134                }
135            });
136            return this;
137        }
138
139        /**
140         * Add multiple buttons.
141         * @param numButtons the number of views to add.
142         * @param textPrefix The text to prepend to each button.
143         * @param heightRatio The view's height will be this * the screen height.
144         */
145        public Params addButtons(int numButtons, String textPrefix, float heightRatio) {
146            for (int i = 0; i < numButtons; i++) {
147                addButton(textPrefix + i, heightRatio);
148            }
149            return this;
150        }
151
152        /**
153         * Add an {@link InternalSelectionView}.
154         * @param numRows The number of rows in the internal selection view.
155         * @param heightRatio The view's height will be this * the screen height.
156         */
157        public Params addInternalSelectionView(final int numRows, float heightRatio) {
158            mViewFactories.add(new ViewFactoryBase(heightRatio) {
159                public View create(final Context context) {
160                    return new InternalSelectionView(context, numRows, "isv");
161                }
162            });
163            return this;
164        }
165
166        /**
167         * Add a sublayout of buttons as a single child of the scroll view.
168         * @param numButtons The number of buttons in the sub layout
169         * @param heightRatio The layout's height will be this * the screen height.
170         */
171        public Params addVerticalLLOfButtons(final String prefix, final int numButtons, float heightRatio) {
172            mViewFactories.add(new ViewFactoryBase(heightRatio) {
173
174                public View create(Context context) {
175                    final LinearLayout ll = new LinearLayout(context);
176                    ll.setOrientation(LinearLayout.VERTICAL);
177
178                    // fill width, equally weighted on height
179                    final LinearLayout.LayoutParams lp =
180                            new LinearLayout.LayoutParams(
181                                    ViewGroup.LayoutParams.MATCH_PARENT, 0, 1f);
182                    for (int i = 0; i < numButtons; i++) {
183                        final Button button = new Button(context);
184                        button.setText(prefix + i);
185                        ll.addView(button, lp);
186                    }
187
188                    return ll;
189                }
190            });
191            return this;
192        }
193
194        public Params addPaddingToScrollView(int topPadding, int bottomPadding) {
195            mTopPadding = topPadding;
196            mBottomPadding = bottomPadding;
197
198            return this;
199        }
200    }
201
202    /**
203     * Override this and initialized the views in the scroll view.
204     * @param params Used to configure the contents of the scroll view.
205     */
206    protected abstract void init(Params params);
207
208    public LinearLayout getLinearLayout() {
209        return mLinearLayout;
210    }
211
212    public ScrollView getScrollView() {
213        return mScrollView;
214    }
215
216    /**
217     * Get the child contained within the vertical linear layout of the
218     * scroll view.
219     * @param index The index within the linear layout.
220     * @return the child within the vertical linear layout of the scroll view
221     *   at the specified index.
222     */
223    @SuppressWarnings({"unchecked"})
224    public <T extends View> T getContentChildAt(int index) {
225        return (T) mLinearLayout.getChildAt(index);
226    }
227
228    /**
229     * Hook for changing how scroll view's are created.
230     */
231    @SuppressWarnings({"JavaDoc"})
232    protected ScrollView createScrollView() {
233        return new ScrollView(this);
234    }
235
236    @Override
237    protected void onCreate(Bundle savedInstanceState) {
238        super.onCreate(savedInstanceState);
239
240        // for test stability, turn off title bar
241        requestWindowFeature(Window.FEATURE_NO_TITLE);
242        int screenHeight = getWindowManager().getDefaultDisplay().getHeight()
243                - 25;
244        mLinearLayout = new LinearLayout(this);
245        mLinearLayout.setOrientation(LinearLayout.VERTICAL);
246
247        // initialize params
248        final Params params = new Params();
249        init(params);
250
251        // create views specified by params
252        for (ViewFactory viewFactory : params.mViewFactories) {
253            int height = ViewGroup.LayoutParams.WRAP_CONTENT;
254            if (viewFactory.getHeightRatio() >= 0) {
255                height = (int) (viewFactory.getHeightRatio() * screenHeight);
256            }
257            final LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
258                    ViewGroup.LayoutParams.MATCH_PARENT, height);
259            mLinearLayout.addView(viewFactory.create(this), lp);
260        }
261
262        mScrollView = createScrollView();
263        mScrollView.setPadding(0, params.mTopPadding, 0, params.mBottomPadding);
264        mScrollView.addView(mLinearLayout, new ViewGroup.LayoutParams(
265                ViewGroup.LayoutParams.MATCH_PARENT,
266                ViewGroup.LayoutParams.MATCH_PARENT));
267
268        // no animation to speed up tests
269        mScrollView.setSmoothScrollingEnabled(false);
270
271        setContentView(mScrollView);
272    }
273}
274