1 /* 2 * Copyright (C) 2006 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 17 package android.view; 18 19 import android.util.DisplayMetrics; 20 21 public class Display 22 { 23 /** 24 * Specify the default Display 25 */ 26 public static final int DEFAULT_DISPLAY = 0; 27 28 29 /** 30 * Use {@link android.view.WindowManager#getDefaultDisplay() 31 * WindowManager.getDefaultDisplay()} to create a Display object. 32 * Display gives you access to some information about a particular display 33 * connected to the device. 34 */ 35 Display(int display) { 36 // initalize the statics when this class is first instansiated. This is 37 // done here instead of in the static block because Zygote 38 synchronized (mStaticInit) { 39 if (!mInitialized) { 40 nativeClassInit(); 41 mInitialized = true; 42 } 43 } 44 mDisplay = display; 45 init(display); 46 } 47 48 /** 49 * Returns the index of this display. This is currently undefined; do 50 * not use. 51 */ 52 public int getDisplayId() { 53 return mDisplay; 54 } 55 56 /** 57 * Returns the number of displays connected to the device. This is 58 * currently undefined; do not use. 59 */ 60 native static int getDisplayCount(); 61 62 /** 63 * Returns the raw width of the display, in pixels. Note that this 64 * should <em>not</em> generally be used for computing layouts, since 65 * a device will typically have screen decoration (such as a status bar) 66 * along the edges of the display that reduce the amount of application 67 * space available from the raw size returned here. This value is 68 * adjusted for you based on the current rotation of the display. 69 */ 70 native public int getWidth(); 71 72 /** 73 * Returns the raw height of the display, in pixels. Note that this 74 * should <em>not</em> generally be used for computing layouts, since 75 * a device will typically have screen decoration (such as a status bar) 76 * along the edges of the display that reduce the amount of application 77 * space available from the raw size returned here. This value is 78 * adjusted for you based on the current rotation of the display. 79 */ 80 native public int getHeight(); 81 82 /** 83 * Returns the rotation of the screen from its "natural" orientation. 84 * The returned value may be {@link Surface#ROTATION_0 Surface.ROTATION_0} 85 * (no rotation), {@link Surface#ROTATION_90 Surface.ROTATION_90}, 86 * {@link Surface#ROTATION_180 Surface.ROTATION_180}, or 87 * {@link Surface#ROTATION_270 Surface.ROTATION_270}. For 88 * example, if a device has a naturally tall screen, and the user has 89 * turned it on its side to go into a landscape orientation, the value 90 * returned here may be either {@link Surface#ROTATION_90 Surface.ROTATION_90} 91 * or {@link Surface#ROTATION_270 Surface.ROTATION_270} depending on 92 * the direction it was turned. The angle is the rotation of the drawn 93 * graphics on the screen, which is the opposite direction of the physical 94 * rotation of the device. For example, if the device is rotated 90 95 * degrees counter-clockwise, to compensate rendering will be rotated by 96 * 90 degrees clockwise and thus the returned value here will be 97 * {@link Surface#ROTATION_90 Surface.ROTATION_90}. 98 */ 99 public int getRotation() { 100 return getOrientation(); 101 } 102 103 /** 104 * @deprecated use {@link #getRotation} 105 * @return orientation of this display. 106 */ 107 @Deprecated native public int getOrientation(); 108 109 /** 110 * Return the native pixel format of the display. The returned value 111 * may be one of the constants int {@link android.graphics.PixelFormat}. 112 */ 113 public int getPixelFormat() { 114 return mPixelFormat; 115 } 116 117 /** 118 * Return the refresh rate of this display in frames per second. 119 */ 120 public float getRefreshRate() { 121 return mRefreshRate; 122 } 123 124 /** 125 * Initialize a DisplayMetrics object from this display's data. 126 * 127 * @param outMetrics 128 */ 129 public void getMetrics(DisplayMetrics outMetrics) { 130 outMetrics.widthPixels = getWidth(); 131 outMetrics.heightPixels = getHeight(); 132 outMetrics.density = mDensity; 133 outMetrics.densityDpi = (int)((mDensity*DisplayMetrics.DENSITY_DEFAULT)+.5f); 134 outMetrics.scaledDensity= outMetrics.density; 135 outMetrics.xdpi = mDpiX; 136 outMetrics.ydpi = mDpiY; 137 } 138 139 /* 140 * We use a class initializer to allow the native code to cache some 141 * field offsets. 142 */ 143 native private static void nativeClassInit(); 144 145 private native void init(int display); 146 147 private int mDisplay; 148 // Following fields are initialized from native code 149 private int mPixelFormat; 150 private float mRefreshRate; 151 private float mDensity; 152 private float mDpiX; 153 private float mDpiY; 154 155 private static final Object mStaticInit = new Object(); 156 private static boolean mInitialized = false; 157 158 /** 159 * Returns a display object which uses the metric's width/height instead. 160 * @hide 161 */ 162 public static Display createMetricsBasedDisplay(int displayId, DisplayMetrics metrics) { 163 return new CompatibleDisplay(displayId, metrics); 164 } 165 166 private static class CompatibleDisplay extends Display { 167 private final DisplayMetrics mMetrics; 168 169 private CompatibleDisplay(int displayId, DisplayMetrics metrics) { 170 super(displayId); 171 mMetrics = metrics; 172 } 173 174 @Override 175 public int getWidth() { 176 return mMetrics.widthPixels; 177 } 178 179 @Override 180 public int getHeight() { 181 return mMetrics.heightPixels; 182 } 183 } 184 } 185 186
