DisplayInfoManager.java
/*
* Copyright 2021 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.camera.camera2.internal;
import android.content.Context;
import android.graphics.Point;
import android.hardware.display.DisplayManager;
import android.util.Size;
import android.view.Display;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.annotation.VisibleForTesting;
import androidx.camera.camera2.internal.compat.workaround.MaxPreviewSize;
/**
* A singleton class to retrieve display related information.
*/
@RequiresApi(21) // TODO(b/200306659): Remove and replace with annotation on package-info.java
public class DisplayInfoManager {
private static final Size MAX_PREVIEW_SIZE = new Size(1920, 1080);
private static final Object INSTANCE_LOCK = new Object();
private static volatile DisplayInfoManager sInstance;
@NonNull
private final DisplayManager mDisplayManager;
private volatile Size mPreviewSize = null;
private final MaxPreviewSize mMaxPreviewSize = new MaxPreviewSize();
private DisplayInfoManager(@NonNull Context context) {
mDisplayManager = (DisplayManager) context.getSystemService(Context.DISPLAY_SERVICE);
}
/**
* Gets the singleton instance of DisplayInfoManager.
*/
@NonNull
public static DisplayInfoManager getInstance(@NonNull Context context) {
if (sInstance == null) {
synchronized (INSTANCE_LOCK) {
if (sInstance == null) {
sInstance = new DisplayInfoManager(context);
}
}
}
return sInstance;
}
/**
* Test purpose only. To release the instance so that the test can create a new instance.
*/
@VisibleForTesting
static void releaseInstance() {
sInstance = null;
}
/**
* Update the preview size according to current display size.
*/
void refresh() {
mPreviewSize = calculatePreviewSize();
}
/**
* Retrieves the display which has the max size among all displays.
*/
@SuppressWarnings("deprecation") /* getRealSize */
@NonNull
public Display getMaxSizeDisplay() {
Display[] displays = mDisplayManager.getDisplays();
if (displays.length == 1) {
return displays[0];
}
Display maxDisplay = null;
int maxDisplaySize = -1;
for (Display display : displays) {
if (display.getState() != Display.STATE_OFF) {
Point displaySize = new Point();
display.getRealSize(displaySize);
if (displaySize.x * displaySize.y > maxDisplaySize) {
maxDisplaySize = displaySize.x * displaySize.y;
maxDisplay = display;
}
}
}
if (maxDisplay == null) {
throw new IllegalArgumentException("No display can be found from the input display "
+ "manager!");
}
return maxDisplay;
}
/**
* PREVIEW refers to the best size match to the device's screen resolution, or to 1080p
* (1920x1080), whichever is smaller.
*/
@NonNull
Size getPreviewSize() {
// Use cached value to speed up since this would be called multiple times.
if (mPreviewSize != null) {
return mPreviewSize;
}
mPreviewSize = calculatePreviewSize();
return mPreviewSize;
}
@SuppressWarnings("deprecation") /* getRealSize */
private Size calculatePreviewSize() {
Point displaySize = new Point();
Display display = getMaxSizeDisplay();
display.getRealSize(displaySize);
Size displayViewSize;
if (displaySize.x > displaySize.y) {
displayViewSize = new Size(displaySize.x, displaySize.y);
} else {
displayViewSize = new Size(displaySize.y, displaySize.x);
}
if (displayViewSize.getWidth() * displayViewSize.getHeight()
> MAX_PREVIEW_SIZE.getWidth() * MAX_PREVIEW_SIZE.getHeight()) {
displayViewSize = MAX_PREVIEW_SIZE;
}
return mMaxPreviewSize.getMaxPreviewResolution(displayViewSize);
}
}