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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.util;
18 
19 import static com.android.window.flags.Flags.FLAG_DENSITY_390_API;
20 
21 import android.annotation.FlaggedApi;
22 import android.annotation.IntDef;
23 import android.annotation.Nullable;
24 import android.compat.annotation.UnsupportedAppUsage;
25 import android.content.res.FontScaleConverter;
26 import android.os.SystemProperties;
27 import android.view.WindowManager;
28 
29 import java.lang.annotation.Retention;
30 import java.lang.annotation.RetentionPolicy;
31 
32 /**
33  * A structure describing general information about a display, such as its
34  * size, density, and font scaling.
35  * <p>To access the DisplayMetrics members, retrieve display metrics like this:</p>
36  * <pre>context.getResources().getDisplayMetrics();</pre>
37  *
38  * <p>
39  * For UI layout, obtain {@link android.view.WindowMetrics} from
40  * {@link WindowManager#getCurrentWindowMetrics()}. {@code DisplayMetrics} should only be used for
41  * obtaining display related properties, such as {@link #xdpi} and {@link #ydpi}
42  * </p><p>
43  * See {@link #density} for more information about the differences between {@link #xdpi},
44  * {@link #ydpi} and {@link #density}.
45  * </p>
46  *
47  */
48 public class DisplayMetrics {
49 
50     @IntDef(prefix = { "DENSITY_" }, value = {
51             DENSITY_LOW,
52             DENSITY_140,
53             DENSITY_MEDIUM,
54             DENSITY_180,
55             DENSITY_200,
56             DENSITY_TV,
57             DENSITY_220,
58             DENSITY_HIGH,
59             DENSITY_260,
60             DENSITY_280,
61             DENSITY_300,
62             DENSITY_XHIGH,
63             DENSITY_340,
64             DENSITY_360,
65             DENSITY_390,
66             DENSITY_400,
67             DENSITY_420,
68             DENSITY_440,
69             DENSITY_450,
70             DENSITY_XXHIGH,
71             DENSITY_520,
72             DENSITY_560,
73             DENSITY_600,
74             DENSITY_XXXHIGH,
75     })
76     @Retention(RetentionPolicy.SOURCE)
77     @interface DensityDpi{}
78 
79     /**
80      * Standard quantized DPI for low-density screens.
81      */
82     public static final int DENSITY_LOW = 120;
83 
84     /**
85      * Intermediate density for screens that sit between {@link #DENSITY_LOW} (120dpi) and
86      * {@link #DENSITY_MEDIUM} (160dpi). This is not a density that applications should target,
87      * instead relying on the system to scale their {@link #DENSITY_MEDIUM} assets for them.
88      */
89     public static final int DENSITY_140 = 140;
90 
91     /**
92      * Standard quantized DPI for medium-density screens.
93      */
94     public static final int DENSITY_MEDIUM = 160;
95 
96     /**
97      * Intermediate density for screens that sit between {@link #DENSITY_MEDIUM} (160dpi) and
98      * {@link #DENSITY_HIGH} (240dpi). This is not a density that applications should target,
99      * instead relying on the system to scale their {@link #DENSITY_HIGH} assets for them.
100      */
101     public static final int DENSITY_180 = 180;
102 
103     /**
104      * Intermediate density for screens that sit between {@link #DENSITY_MEDIUM} (160dpi) and
105      * {@link #DENSITY_HIGH} (240dpi). This is not a density that applications should target,
106      * instead relying on the system to scale their {@link #DENSITY_HIGH} assets for them.
107      */
108     public static final int DENSITY_200 = 200;
109 
110     /**
111      * This is a secondary density, added for some common screen configurations.
112      * It is recommended that applications not generally target this as a first
113      * class density -- that is, don't supply specific graphics for this
114      * density, instead allow the platform to scale from other densities
115      * (typically {@link #DENSITY_HIGH}) as
116      * appropriate.  In most cases (such as using bitmaps in
117      * {@link android.graphics.drawable.Drawable}) the platform
118      * can perform this scaling at load time, so the only cost is some slight
119      * startup runtime overhead.
120      *
121      * <p>This density was original introduced to correspond with a
122      * 720p TV screen: the density for 1080p televisions is
123      * {@link #DENSITY_XHIGH}, and the value here provides the same UI
124      * size for a TV running at 720p.  It has also found use in 7" tablets,
125      * when these devices have 1280x720 displays.
126      */
127     public static final int DENSITY_TV = 213;
128 
129     /**
130      * Intermediate density for screens that sit between {@link #DENSITY_MEDIUM} (160dpi) and
131      * {@link #DENSITY_HIGH} (240dpi). This is not a density that applications should target,
132      * instead relying on the system to scale their {@link #DENSITY_HIGH} assets for them.
133      */
134     public static final int DENSITY_220 = 220;
135 
136     /**
137      * Standard quantized DPI for high-density screens.
138      */
139     public static final int DENSITY_HIGH = 240;
140 
141     /**
142      * Intermediate density for screens that sit between {@link #DENSITY_HIGH} (240dpi) and
143      * {@link #DENSITY_XHIGH} (320dpi). This is not a density that applications should target,
144      * instead relying on the system to scale their {@link #DENSITY_XHIGH} assets for them.
145      */
146     public static final int DENSITY_260 = 260;
147 
148     /**
149      * Intermediate density for screens that sit between {@link #DENSITY_HIGH} (240dpi) and
150      * {@link #DENSITY_XHIGH} (320dpi). This is not a density that applications should target,
151      * instead relying on the system to scale their {@link #DENSITY_XHIGH} assets for them.
152      */
153     public static final int DENSITY_280 = 280;
154 
155     /**
156      * Intermediate density for screens that sit between {@link #DENSITY_HIGH} (240dpi) and
157      * {@link #DENSITY_XHIGH} (320dpi). This is not a density that applications should target,
158      * instead relying on the system to scale their {@link #DENSITY_XHIGH} assets for them.
159      */
160     public static final int DENSITY_300 = 300;
161 
162     /**
163      * Standard quantized DPI for extra-high-density screens.
164      */
165     public static final int DENSITY_XHIGH = 320;
166 
167     /**
168      * Intermediate density for screens that sit somewhere between
169      * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
170      * This is not a density that applications should target, instead relying
171      * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
172      */
173     public static final int DENSITY_340 = 340;
174 
175     /**
176      * Intermediate density for screens that sit somewhere between
177      * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
178      * This is not a density that applications should target, instead relying
179      * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
180      */
181     public static final int DENSITY_360 = 360;
182 
183     /**
184      * Intermediate density for screens that sit somewhere between
185      * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
186      * This is not a density that applications should target, instead relying
187      * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
188      */
189     @FlaggedApi(FLAG_DENSITY_390_API)
190     public static final int DENSITY_390 = 390;
191 
192     /**
193      * Intermediate density for screens that sit somewhere between
194      * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
195      * This is not a density that applications should target, instead relying
196      * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
197      */
198     public static final int DENSITY_400 = 400;
199 
200     /**
201      * Intermediate density for screens that sit somewhere between
202      * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
203      * This is not a density that applications should target, instead relying
204      * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
205      */
206     public static final int DENSITY_420 = 420;
207 
208     /**
209      * Intermediate density for screens that sit somewhere between
210      * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
211      * This is not a density that applications should target, instead relying
212      * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
213      */
214     public static final int DENSITY_440 = 440;
215 
216     /**
217      * Intermediate density for screens that sit somewhere between
218      * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
219      * This is not a density that applications should target, instead relying
220      * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
221      */
222     public static final int DENSITY_450 = 450;
223 
224     /**
225      * Standard quantized DPI for extra-extra-high-density screens.
226      */
227     public static final int DENSITY_XXHIGH = 480;
228 
229     /**
230      * Intermediate density for screens that sit somewhere between
231      * {@link #DENSITY_XXHIGH} (480 dpi) and {@link #DENSITY_XXXHIGH} (640 dpi).
232      * This is not a density that applications should target, instead relying
233      * on the system to scale their {@link #DENSITY_XXXHIGH} assets for them.
234      */
235     public static final int DENSITY_520 = 520;
236 
237     /**
238      * Intermediate density for screens that sit somewhere between
239      * {@link #DENSITY_XXHIGH} (480 dpi) and {@link #DENSITY_XXXHIGH} (640 dpi).
240      * This is not a density that applications should target, instead relying
241      * on the system to scale their {@link #DENSITY_XXXHIGH} assets for them.
242      */
243     public static final int DENSITY_560 = 560;
244 
245     /**
246      * Intermediate density for screens that sit somewhere between
247      * {@link #DENSITY_XXHIGH} (480 dpi) and {@link #DENSITY_XXXHIGH} (640 dpi).
248      * This is not a density that applications should target, instead relying
249      * on the system to scale their {@link #DENSITY_XXXHIGH} assets for them.
250      */
251     public static final int DENSITY_600 = 600;
252 
253     /**
254      * Standard quantized DPI for extra-extra-extra-high-density screens.  Applications
255      * should not generally worry about this density; relying on XHIGH graphics
256      * being scaled up to it should be sufficient for almost all cases.  A typical
257      * use of this density would be 4K television screens -- 3840x2160, which
258      * is 2x a traditional HD 1920x1080 screen which runs at DENSITY_XHIGH.
259      */
260     public static final int DENSITY_XXXHIGH = 640;
261 
262     /**
263      * The reference density used throughout the system.
264      */
265     public static final int DENSITY_DEFAULT = DENSITY_MEDIUM;
266 
267     /**
268      * Scaling factor to convert a density in DPI units to the density scale.
269      * @hide
270      */
271     public static final float DENSITY_DEFAULT_SCALE = 1.0f / DENSITY_DEFAULT;
272 
273     /**
274      * The device's current density.
275      * <p>
276      * This value reflects any changes made to the device density. To obtain
277      * the device's stable density, use {@link #DENSITY_DEVICE_STABLE}.
278      *
279      * @hide This value should not be used.
280      * @deprecated Use {@link #DENSITY_DEVICE_STABLE} to obtain the stable
281      *             device density or {@link #densityDpi} to obtain the current
282      *             density for a specific display.
283      */
284     @Deprecated
285     @UnsupportedAppUsage
286     public static int DENSITY_DEVICE = getDeviceDensity();
287 
288     /**
289      * The device's stable density.
290      * <p>
291      * This value is constant at run time and may not reflect the current
292      * display density. To obtain the current density for a specific display,
293      * use {@link #densityDpi}.
294      */
295     public static final int DENSITY_DEVICE_STABLE = getDeviceDensity();
296 
297     /**
298      * The absolute width of the available display size in pixels.
299      */
300     public int widthPixels;
301     /**
302      * The absolute height of the available display size in pixels.
303      */
304     public int heightPixels;
305     /**
306      * The logical density of the display.  This is a scaling factor for the
307      * Density Independent Pixel unit, where one DIP is one pixel on an
308      * approximately 160 dpi screen (for example a 240x320, 1.5"x2" screen),
309      * providing the baseline of the system's display. Thus on a 160dpi screen
310      * this density value will be 1; on a 120 dpi screen it would be .75; etc.
311      *
312      * <p>This value does not exactly follow the real screen size (as given by
313      * {@link #xdpi} and {@link #ydpi}), but rather is used to scale the size of
314      * the overall UI in steps based on gross changes in the display dpi.  For
315      * example, a 240x320 screen will have a density of 1 even if its width is
316      * 1.8", 1.3", etc. However, if the screen resolution is increased to
317      * 320x480 but the screen size remained 1.5"x2" then the density would be
318      * increased (probably to 1.5).
319      *
320      * @see #DENSITY_DEFAULT
321      */
322     public float density;
323     /**
324      * The screen density expressed as dots-per-inch. May be any one of the
325      * {@code DENSITY_} constants defined above.
326      *
327      * New constants are frequently added, and constants added on new Android
328      * versions may be backported to previous Android versions, so applications
329      * should not strongly rely on density matching one of the enum constants.
330      */
331     @DensityDpi
332     public int densityDpi;
333     /**
334      * A scaling factor for fonts displayed on the display.  This is the same
335      * as {@link #density}, except that it may be adjusted in smaller
336      * increments at runtime based on a user preference for the font size.
337      *
338      * @deprecated this scalar factor is no longer accurate due to adaptive non-linear font scaling.
339      *  Please use {@link TypedValue#applyDimension(int, float, DisplayMetrics)} or
340      *  {@link TypedValue#deriveDimension(int, float, DisplayMetrics)} to convert between SP font
341      *  sizes and pixels.
342      */
343     @Deprecated
344     public float scaledDensity;
345 
346     /**
347      * If non-null, this will be used to calculate font sizes instead of {@link #scaledDensity}.
348      *
349      * @hide
350      */
351     @Nullable
352     public FontScaleConverter fontScaleConverter;
353 
354     /**
355      * The exact physical pixels per inch of the screen in the X dimension.
356      */
357     public float xdpi;
358     /**
359      * The exact physical pixels per inch of the screen in the Y dimension.
360      */
361     public float ydpi;
362 
363     /**
364      * The reported display width prior to any compatibility mode scaling
365      * being applied.
366      * @hide
367      */
368     @UnsupportedAppUsage
369     public int noncompatWidthPixels;
370     /**
371      * The reported display height prior to any compatibility mode scaling
372      * being applied.
373      * @hide
374      */
375     @UnsupportedAppUsage
376     public int noncompatHeightPixels;
377     /**
378      * The reported display density prior to any compatibility mode scaling
379      * being applied.
380      * @hide
381      */
382     public float noncompatDensity;
383     /**
384      * The reported display density prior to any compatibility mode scaling
385      * being applied.
386      * @hide
387      */
388     @UnsupportedAppUsage
389     public int noncompatDensityDpi;
390     /**
391      * The reported scaled density prior to any compatibility mode scaling
392      * being applied.
393      * @hide
394      */
395     public float noncompatScaledDensity;
396     /**
397      * The reported display xdpi prior to any compatibility mode scaling
398      * being applied.
399      * @hide
400      */
401     public float noncompatXdpi;
402     /**
403      * The reported display ydpi prior to any compatibility mode scaling
404      * being applied.
405      * @hide
406      */
407     public float noncompatYdpi;
408 
DisplayMetrics()409     public DisplayMetrics() {
410     }
411 
setTo(DisplayMetrics o)412     public void setTo(DisplayMetrics o) {
413         if (this == o) {
414             return;
415         }
416 
417         widthPixels = o.widthPixels;
418         heightPixels = o.heightPixels;
419         density = o.density;
420         densityDpi = o.densityDpi;
421         scaledDensity = o.scaledDensity;
422         xdpi = o.xdpi;
423         ydpi = o.ydpi;
424         noncompatWidthPixels = o.noncompatWidthPixels;
425         noncompatHeightPixels = o.noncompatHeightPixels;
426         noncompatDensity = o.noncompatDensity;
427         noncompatDensityDpi = o.noncompatDensityDpi;
428         noncompatScaledDensity = o.noncompatScaledDensity;
429         noncompatXdpi = o.noncompatXdpi;
430         noncompatYdpi = o.noncompatYdpi;
431         fontScaleConverter = o.fontScaleConverter;
432     }
433 
setToDefaults()434     public void setToDefaults() {
435         widthPixels = 0;
436         heightPixels = 0;
437         density =  DENSITY_DEVICE / (float) DENSITY_DEFAULT;
438         densityDpi =  DENSITY_DEVICE;
439         scaledDensity = density;
440         xdpi = DENSITY_DEVICE;
441         ydpi = DENSITY_DEVICE;
442         noncompatWidthPixels = widthPixels;
443         noncompatHeightPixels = heightPixels;
444         noncompatDensity = density;
445         noncompatDensityDpi = densityDpi;
446         noncompatScaledDensity = scaledDensity;
447         noncompatXdpi = xdpi;
448         noncompatYdpi = ydpi;
449         fontScaleConverter = null;
450     }
451 
452     @Override
equals(@ullable Object o)453     public boolean equals(@Nullable Object o) {
454         return o instanceof DisplayMetrics && equals((DisplayMetrics)o);
455     }
456 
457     /**
458      * Returns true if these display metrics equal the other display metrics.
459      *
460      * @param other The display metrics with which to compare.
461      * @return True if the display metrics are equal.
462      */
equals(DisplayMetrics other)463     public boolean equals(DisplayMetrics other) {
464         return equalsPhysical(other)
465                 && scaledDensity == other.scaledDensity
466                 && noncompatScaledDensity == other.noncompatScaledDensity;
467     }
468 
469     /**
470      * Returns true if the physical aspects of the two display metrics
471      * are equal.  This ignores the scaled density, which is a logical
472      * attribute based on the current desired font size.
473      *
474      * @param other The display metrics with which to compare.
475      * @return True if the display metrics are equal.
476      * @hide
477      */
equalsPhysical(DisplayMetrics other)478     public boolean equalsPhysical(DisplayMetrics other) {
479         return other != null
480                 && widthPixels == other.widthPixels
481                 && heightPixels == other.heightPixels
482                 && density == other.density
483                 && densityDpi == other.densityDpi
484                 && xdpi == other.xdpi
485                 && ydpi == other.ydpi
486                 && noncompatWidthPixels == other.noncompatWidthPixels
487                 && noncompatHeightPixels == other.noncompatHeightPixels
488                 && noncompatDensity == other.noncompatDensity
489                 && noncompatDensityDpi == other.noncompatDensityDpi
490                 && noncompatXdpi == other.noncompatXdpi
491                 && noncompatYdpi == other.noncompatYdpi;
492     }
493 
494     @Override
hashCode()495     public int hashCode() {
496         return widthPixels * heightPixels * densityDpi;
497     }
498 
499     @Override
toString()500     public String toString() {
501         return "DisplayMetrics{density=" + density + ", width=" + widthPixels +
502             ", height=" + heightPixels + ", scaledDensity=" + scaledDensity +
503             ", xdpi=" + xdpi + ", ydpi=" + ydpi + "}";
504     }
505 
getDeviceDensity()506     private static int getDeviceDensity() {
507         // qemu.sf.lcd_density can be used to override ro.sf.lcd_density
508         // when running in the emulator, allowing for dynamic configurations.
509         // The reason for this is that ro.sf.lcd_density is write-once and is
510         // set by the init process when it parses build.prop before anything else.
511         return SystemProperties.getInt("qemu.sf.lcd_density",
512                 SystemProperties.getInt("ro.sf.lcd_density", DENSITY_DEFAULT));
513     }
514 }
515