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     */
65    private static abstract class ViewFactoryBase implements ViewFactory {
66
67        private float mHeightRatio;
68
69        @SuppressWarnings({"UnusedDeclaration"})
70        private ViewFactoryBase() {throw new UnsupportedOperationException("don't call this!");}
71
72        protected ViewFactoryBase(float heightRatio) {
73            mHeightRatio = heightRatio;
74        }
75
76        public float getHeightRatio() {
77            return mHeightRatio;
78        }
79    }
80
81    /**
82     * Builder for selecting the views to be vertically arranged in the scroll
83     * view.
84     */
85    @SuppressWarnings({"JavaDoc"})
86    public static class Params {
87
88        List<ViewFactory> mViewFactories = Lists.newArrayList();
89
90        /**
91         * Add a text view.
92         * @param text The text of the text view.
93         * @param heightRatio The view's height will be this * the screen height.
94         */
95        public Params addTextView(final String text, float heightRatio) {
96            mViewFactories.add(new ViewFactoryBase(heightRatio) {
97                public View create(final Context context) {
98                    final TextView tv = new TextView(context);
99                    tv.setText(text);
100                    return tv;
101                }
102            });
103            return this;
104        }
105
106        /**
107         * Add multiple text views.
108         * @param numViews the number of views to add.
109         * @param textPrefix The text to prepend to each text view.
110         * @param heightRatio The view's height will be this * the screen height.
111         */
112        public Params addTextViews(int numViews, String textPrefix, float heightRatio) {
113            for (int i = 0; i < numViews; i++) {
114                addTextView(textPrefix + i, heightRatio);
115            }
116            return this;
117        }
118
119        /**
120         * Add a button.
121         * @param text The text of the button.
122         * @param heightRatio The view's height will be this * the screen height.
123         */
124        public Params addButton(final String text, float heightRatio) {
125            mViewFactories.add(new ViewFactoryBase(heightRatio) {
126                public View create(final Context context) {
127                    final Button button = new Button(context);
128                    button.setText(text);
129                    return button;
130                }
131            });
132            return this;
133        }
134
135        /**
136         * Add multiple buttons.
137         * @param numButtons the number of views to add.
138         * @param textPrefix The text to prepend to each button.
139         * @param heightRatio The view's height will be this * the screen height.
140         */
141        public Params addButtons(int numButtons, String textPrefix, float heightRatio) {
142            for (int i = 0; i < numButtons; i++) {
143                addButton(textPrefix + i, heightRatio);
144            }
145            return this;
146        }
147
148        /**
149         * Add an {@link InternalSelectionView}.
150         * @param numRows The number of rows in the internal selection view.
151         * @param heightRatio The view's height will be this * the screen height.
152         */
153        public Params addInternalSelectionView(final int numRows, float heightRatio) {
154            mViewFactories.add(new ViewFactoryBase(heightRatio) {
155                public View create(final Context context) {
156                    return new InternalSelectionView(context, numRows, "isv");
157                }
158            });
159            return this;
160        }
161
162        /**
163         * Add a sublayout of buttons as a single child of the scroll view.
164         * @param numButtons The number of buttons in the sub layout
165         * @param heightRatio The layout's height will be this * the screen height.
166         */
167        public Params addVerticalLLOfButtons(final String prefix, final int numButtons, float heightRatio) {
168            mViewFactories.add(new ViewFactoryBase(heightRatio) {
169
170                public View create(Context context) {
171                    final LinearLayout ll = new LinearLayout(context);
172                    ll.setOrientation(LinearLayout.VERTICAL);
173
174                    // fill width, equally weighted on height
175                    final LinearLayout.LayoutParams lp =
176                            new LinearLayout.LayoutParams(
177                                    ViewGroup.LayoutParams.MATCH_PARENT, 0, 1f);
178                    for (int i = 0; i < numButtons; i++) {
179                        final Button button = new Button(context);
180                        button.setText(prefix + i);
181                        ll.addView(button, lp);
182                    }
183
184                    return ll;
185                }
186            });
187            return this;
188        }
189    }
190
191    /**
192     * Override this and initialized the views in the scroll view.
193     * @param params Used to configure the contents of the scroll view.
194     */
195    protected abstract void init(Params params);
196
197    public LinearLayout getLinearLayout() {
198        return mLinearLayout;
199    }
200
201    public ScrollView getScrollView() {
202        return mScrollView;
203    }
204
205    /**
206     * Get the child contained within the vertical linear layout of the
207     * scroll view.
208     * @param index The index within the linear layout.
209     * @return the child within the vertical linear layout of the scroll view
210     *   at the specified index.
211     */
212    @SuppressWarnings({"unchecked"})
213    public <T extends View> T getContentChildAt(int index) {
214        return (T) mLinearLayout.getChildAt(index);
215    }
216
217    /**
218     * Hook for changing how scroll view's are created.
219     */
220    @SuppressWarnings({"JavaDoc"})
221    protected ScrollView createScrollView() {
222        return new ScrollView(this);
223    }
224
225    @Override
226    protected void onCreate(Bundle savedInstanceState) {
227        super.onCreate(savedInstanceState);
228
229        // for test stability, turn off title bar
230        requestWindowFeature(Window.FEATURE_NO_TITLE);
231        int screenHeight = getWindowManager().getDefaultDisplay().getHeight()
232                - 25;
233        mLinearLayout = new LinearLayout(this);
234        mLinearLayout.setOrientation(LinearLayout.VERTICAL);
235
236        // initialize params
237        final Params params = new Params();
238        init(params);
239
240        // create views specified by params
241        for (ViewFactory viewFactory : params.mViewFactories) {
242            final LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
243                    ViewGroup.LayoutParams.MATCH_PARENT,
244                    (int) (viewFactory.getHeightRatio() * screenHeight));
245            mLinearLayout.addView(viewFactory.create(this), lp);
246        }
247
248        mScrollView = createScrollView();
249        mScrollView.addView(mLinearLayout, new ViewGroup.LayoutParams(
250                ViewGroup.LayoutParams.MATCH_PARENT,
251                ViewGroup.LayoutParams.MATCH_PARENT));
252
253        // no animation to speed up tests
254        mScrollView.setSmoothScrollingEnabled(false);
255
256        setContentView(mScrollView);
257    }
258}
259