DensityActivity.java revision 62e92d7a2a3fd2798901ec2e7c452ff0e4067163 
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 com.example.android.apis.graphics;
18
19//Need the following import to get access to the app resources, since this
20//class is in a sub-package.
21import com.example.android.apis.R;
22
23import android.app.Activity;
24import android.os.Bundle;
25import android.graphics.BitmapFactory;
26import android.graphics.Bitmap;
27import android.graphics.Canvas;
28import android.graphics.drawable.BitmapDrawable;
29import android.graphics.drawable.Drawable;
30import android.widget.LinearLayout;
31import android.widget.TextView;
32import android.widget.ScrollView;
33import android.view.LayoutInflater;
34import android.view.View;
35import android.content.Context;
36import android.util.DisplayMetrics;
37import android.util.Log;
38
39/**
40 * This activity demonstrates various ways density can cause the scaling of
41 * bitmaps and drawables.
42 */
43public class DensityActivity extends Activity {
44    @Override
45    protected void onCreate(Bundle savedInstanceState) {
46        super.onCreate(savedInstanceState);
47
48        final LayoutInflater li = (LayoutInflater)getSystemService(
49                LAYOUT_INFLATER_SERVICE);
50
51        this.setTitle(R.string.density_title);
52        LinearLayout root = new LinearLayout(this);
53        root.setOrientation(LinearLayout.VERTICAL);
54
55        LinearLayout layout = new LinearLayout(this);
56        addBitmapDrawable(layout, R.drawable.logo120dpi, true);
57        addBitmapDrawable(layout, R.drawable.logo160dpi, true);
58        addBitmapDrawable(layout, R.drawable.logo240dpi, true);
59        addLabelToRoot(root, "Prescaled bitmap in drawable");
60        addChildToRoot(root, layout);
61
62        layout = new LinearLayout(this);
63        addBitmapDrawable(layout, R.drawable.logo120dpi, false);
64        addBitmapDrawable(layout, R.drawable.logo160dpi, false);
65        addBitmapDrawable(layout, R.drawable.logo240dpi, false);
66        addLabelToRoot(root, "Autoscaled bitmap in drawable");
67        addChildToRoot(root, layout);
68
69        layout = new LinearLayout(this);
70        addResourceDrawable(layout, R.drawable.logo120dpi);
71        addResourceDrawable(layout, R.drawable.logo160dpi);
72        addResourceDrawable(layout, R.drawable.logo240dpi);
73        addLabelToRoot(root, "Prescaled resource drawable");
74        addChildToRoot(root, layout);
75
76        layout = (LinearLayout)li.inflate(R.layout.density_image_views, null);
77        addLabelToRoot(root, "Inflated layout");
78        addChildToRoot(root, layout);
79
80        layout = (LinearLayout)li.inflate(R.layout.density_styled_image_views, null);
81        addLabelToRoot(root, "Inflated styled layout");
82        addChildToRoot(root, layout);
83
84        layout = new LinearLayout(this);
85        addCanvasBitmap(layout, R.drawable.logo120dpi, true);
86        addCanvasBitmap(layout, R.drawable.logo160dpi, true);
87        addCanvasBitmap(layout, R.drawable.logo240dpi, true);
88        addLabelToRoot(root, "Prescaled bitmap");
89        addChildToRoot(root, layout);
90
91        layout = new LinearLayout(this);
92        addCanvasBitmap(layout, R.drawable.logo120dpi, false);
93        addCanvasBitmap(layout, R.drawable.logo160dpi, false);
94        addCanvasBitmap(layout, R.drawable.logo240dpi, false);
95        addLabelToRoot(root, "Autoscaled bitmap");
96        addChildToRoot(root, layout);
97
98        layout = new LinearLayout(this);
99        addResourceDrawable(layout, R.drawable.logonodpi120);
100        addResourceDrawable(layout, R.drawable.logonodpi160);
101        addResourceDrawable(layout, R.drawable.logonodpi240);
102        addLabelToRoot(root, "No-dpi resource drawable");
103        addChildToRoot(root, layout);
104
105        layout = new LinearLayout(this);
106        addNinePatchResourceDrawable(layout, R.drawable.smlnpatch120dpi);
107        addNinePatchResourceDrawable(layout, R.drawable.smlnpatch160dpi);
108        addNinePatchResourceDrawable(layout, R.drawable.smlnpatch240dpi);
109        addLabelToRoot(root, "Prescaled 9-patch resource drawable");
110        addChildToRoot(root, layout);
111
112        setContentView(scrollWrap(root));
113    }
114
115    private View scrollWrap(View view) {
116        ScrollView scroller = new ScrollView(this);
117        scroller.addView(view, new ScrollView.LayoutParams(ScrollView.LayoutParams.FILL_PARENT,
118                ScrollView.LayoutParams.FILL_PARENT));
119        return scroller;
120    }
121
122    private void addLabelToRoot(LinearLayout root, String text) {
123        TextView label = new TextView(this);
124        label.setText(text);
125        root.addView(label, new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,
126                LinearLayout.LayoutParams.WRAP_CONTENT));
127    }
128
129    private void addChildToRoot(LinearLayout root, LinearLayout layout) {
130        root.addView(layout, new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,
131                LinearLayout.LayoutParams.WRAP_CONTENT));
132    }
133
134    private void addBitmapDrawable(LinearLayout layout, int resource, boolean scale) {
135        Bitmap bitmap;
136        bitmap = loadAndPrintDpi(resource, scale);
137
138        View view = new View(this);
139
140        final BitmapDrawable d = new BitmapDrawable(getResources(), bitmap);
141        if (!scale) d.setTargetDensity(getResources().getDisplayMetrics());
142        view.setBackgroundDrawable(d);
143
144        view.setLayoutParams(new LinearLayout.LayoutParams(d.getIntrinsicWidth(),
145                d.getIntrinsicHeight()));
146        layout.addView(view);
147    }
148
149    private void addResourceDrawable(LinearLayout layout, int resource) {
150        View view = new View(this);
151
152        final Drawable d = getResources().getDrawable(resource);
153        view.setBackgroundDrawable(d);
154
155        view.setLayoutParams(new LinearLayout.LayoutParams(d.getIntrinsicWidth(),
156                d.getIntrinsicHeight()));
157        layout.addView(view);
158    }
159
160    private void addCanvasBitmap(LinearLayout layout, int resource, boolean scale) {
161        Bitmap bitmap;
162        bitmap = loadAndPrintDpi(resource, scale);
163
164        ScaledBitmapView view = new ScaledBitmapView(this, bitmap);
165
166        view.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,
167                LinearLayout.LayoutParams.WRAP_CONTENT));
168        layout.addView(view);
169    }
170
171    private void addNinePatchResourceDrawable(LinearLayout layout, int resource) {
172        View view = new View(this);
173
174        final Drawable d = getResources().getDrawable(resource);
175        view.setBackgroundDrawable(d);
176
177        Log.i("foo", "9-patch #" + Integer.toHexString(resource)
178                + " w=" + d.getIntrinsicWidth() + " h=" + d.getIntrinsicHeight());
179        view.setLayoutParams(new LinearLayout.LayoutParams(
180                d.getIntrinsicWidth()*2, d.getIntrinsicHeight()*2));
181        layout.addView(view);
182    }
183
184    private Bitmap loadAndPrintDpi(int id, boolean scale) {
185        Bitmap bitmap;
186        if (scale) {
187            bitmap = BitmapFactory.decodeResource(getResources(), id);
188        } else {
189            BitmapFactory.Options opts = new BitmapFactory.Options();
190            opts.inScaled = false;
191            bitmap = BitmapFactory.decodeResource(getResources(), id, opts);
192        }
193        return bitmap;
194    }
195
196    private class ScaledBitmapView extends View {
197        private Bitmap mBitmap;
198
199        public ScaledBitmapView(Context context, Bitmap bitmap) {
200            super(context);
201            mBitmap = bitmap;
202        }
203
204        @Override
205        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
206            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
207            final DisplayMetrics metrics = getResources().getDisplayMetrics();
208            setMeasuredDimension(
209                    mBitmap.getScaledWidth(metrics),
210                    mBitmap.getScaledHeight(metrics));
211        }
212
213        @Override
214        protected void onDraw(Canvas canvas) {
215            super.onDraw(canvas);
216
217            canvas.drawBitmap(mBitmap, 0.0f, 0.0f, null);
218        }
219    }
220}
221