/*
* Copyright (C) 2017 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 com.android.server.am;
import android.annotation.IntDef;
import android.app.ActivityOptions;
import android.content.pm.ActivityInfo.WindowLayout;
import android.graphics.Rect;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.ArrayList;
import java.util.List;
import static android.app.WindowConfiguration.WINDOWING_MODE_UNDEFINED;
import static android.view.Display.INVALID_DISPLAY;
import static com.android.server.am.LaunchParamsController.LaunchParamsModifier.RESULT_CONTINUE;
import static com.android.server.am.LaunchParamsController.LaunchParamsModifier.RESULT_DONE;
import static com.android.server.am.LaunchParamsController.LaunchParamsModifier.RESULT_SKIP;
/**
* {@link LaunchParamsController} calculates the {@link LaunchParams} by coordinating between
* registered {@link LaunchParamsModifier}s.
*/
class LaunchParamsController {
private final ActivityManagerService mService;
private final List<LaunchParamsModifier> mModifiers = new ArrayList<>();
// Temporary {@link LaunchParams} for internal calculations. This is kept separate from
// {@code mTmpCurrent} and {@code mTmpResult} to prevent clobbering values.
private final LaunchParams mTmpParams = new LaunchParams();
private final LaunchParams mTmpCurrent = new LaunchParams();
private final LaunchParams mTmpResult = new LaunchParams();
LaunchParamsController(ActivityManagerService service) {
mService = service;
}
/**
* Creates a {@link LaunchParamsController} with default registered
* {@link LaunchParamsModifier}s.
*/
void registerDefaultModifiers(ActivityStackSupervisor supervisor) {
// {@link TaskLaunchParamsModifier} handles window layout preferences.
registerModifier(new TaskLaunchParamsModifier());
// {@link ActivityLaunchParamsModifier} is the most specific modifier and thus should be
// registered last (applied first) out of the defaults.
registerModifier(new ActivityLaunchParamsModifier(supervisor));
}
/**
* Returns the {@link LaunchParams} calculated by the registered modifiers
* @param task The {@link TaskRecord} currently being positioned.
* @param layout The specified {@link WindowLayout}.
* @param activity The {@link ActivityRecord} currently being positioned.
* @param source The {@link ActivityRecord} from which activity was started from.
* @param options The {@link ActivityOptions} specified for the activity.
* @param result The resulting params.
*/
void calculate(TaskRecord task, WindowLayout layout, ActivityRecord activity,
ActivityRecord source, ActivityOptions options, LaunchParams result) {
result.reset();
// We start at the last registered {@link LaunchParamsModifier} as this represents
// The modifier closest to the product level. Moving back through the list moves closer to
// the platform logic.
for (int i = mModifiers.size() - 1; i >= 0; --i) {
mTmpCurrent.set(result);
mTmpResult.reset();
final LaunchParamsModifier modifier = mModifiers.get(i);
switch(modifier.onCalculate(task, layout, activity, source, options, mTmpCurrent,
mTmpResult)) {
case RESULT_SKIP:
// Do not apply any results when we are told to skip
continue;
case RESULT_DONE:
// Set result and return immediately.
result.set(mTmpResult);
return;
case RESULT_CONTINUE:
// Set result and continue
result.set(mTmpResult);
break;
}
}
}
/**
* A convenience method for laying out a task.
* @return {@code true} if bounds were set on the task. {@code false} otherwise.
*/
boolean layoutTask(TaskRecord task, WindowLayout layout) {
return layoutTask(task, layout, null /*activity*/, null /*source*/, null /*options*/);
}
boolean layoutTask(TaskRecord task, WindowLayout layout, ActivityRecord activity,
ActivityRecord source, ActivityOptions options) {
calculate(task, layout, activity, source, options, mTmpParams);
// No changes, return.
if (mTmpParams.isEmpty()) {
return false;
}
mService.mWindowManager.deferSurfaceLayout();
try {
if (mTmpParams.hasPreferredDisplay()
&& mTmpParams.mPreferredDisplayId != task.getStack().getDisplay().mDisplayId) {
mService.moveStackToDisplay(task.getStackId(), mTmpParams.mPreferredDisplayId);
}
if (mTmpParams.hasWindowingMode()
&& mTmpParams.mWindowingMode != task.getStack().getWindowingMode()) {
task.getStack().setWindowingMode(mTmpParams.mWindowingMode);
}
if (!mTmpParams.mBounds.isEmpty()) {
task.updateOverrideConfiguration(mTmpParams.mBounds);
return true;
} else {
return false;
}
} finally {
mService.mWindowManager.continueSurfaceLayout();
}
}
/**
* Adds a modifier to participate in future bounds calculation. Note that the last registered
* {@link LaunchParamsModifier} will be the first to calculate the bounds.
*/
void registerModifier(LaunchParamsModifier modifier) {
if (mModifiers.contains(modifier)) {
return;
}
mModifiers.add(modifier);
}
/**
* A container for holding launch related fields.
*/
static class LaunchParams {
/** The bounds within the parent container. */
final Rect mBounds = new Rect();
/** The id of the display the {@link TaskRecord} would prefer to be on. */
int mPreferredDisplayId;
/** The windowing mode to be in. */
int mWindowingMode;
/** Sets values back to default. {@link #isEmpty} will return {@code true} once called. */
void reset() {
mBounds.setEmpty();
mPreferredDisplayId = INVALID_DISPLAY;
mWindowingMode = WINDOWING_MODE_UNDEFINED;
}
/** Copies the values set on the passed in {@link LaunchParams}. */
void set(LaunchParams params) {
mBounds.set(params.mBounds);
mPreferredDisplayId = params.mPreferredDisplayId;
mWindowingMode = params.mWindowingMode;
}
/** Returns {@code true} if no values have been explicitly set. */
boolean isEmpty() {
return mBounds.isEmpty() && mPreferredDisplayId == INVALID_DISPLAY
&& mWindowingMode == WINDOWING_MODE_UNDEFINED;
}
boolean hasWindowingMode() {
return mWindowingMode != WINDOWING_MODE_UNDEFINED;
}
boolean hasPreferredDisplay() {
return mPreferredDisplayId != INVALID_DISPLAY;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
LaunchParams that = (LaunchParams) o;
if (mPreferredDisplayId != that.mPreferredDisplayId) return false;
if (mWindowingMode != that.mWindowingMode) return false;
return mBounds != null ? mBounds.equals(that.mBounds) : that.mBounds == null;
}
@Override
public int hashCode() {
int result = mBounds != null ? mBounds.hashCode() : 0;
result = 31 * result + mPreferredDisplayId;
result = 31 * result + mWindowingMode;
return result;
}
}
/**
* An interface implemented by those wanting to participate in bounds calculation.
*/
interface LaunchParamsModifier {
@Retention(RetentionPolicy.SOURCE)
@IntDef({RESULT_SKIP, RESULT_DONE, RESULT_CONTINUE})
@interface Result {}
// Returned when the modifier does not want to influence the bounds calculation
int RESULT_SKIP = 0;
// Returned when the modifier has changed the bounds and would like its results to be the
// final bounds applied.
int RESULT_DONE = 1;
// Returned when the modifier has changed the bounds but is okay with other modifiers
// influencing the bounds.
int RESULT_CONTINUE = 2;
/**
* Called when asked to calculate {@link LaunchParams}.
* @param task The {@link TaskRecord} currently being positioned.
* @param layout The specified {@link WindowLayout}.
* @param activity The {@link ActivityRecord} currently being positioned.
* @param source The {@link ActivityRecord} activity was started from.
* @param options The {@link ActivityOptions} specified for the activity.
* @param currentParams The current {@link LaunchParams}. This can differ from the initial
* params as it represents the modified params up to this point.
* @param outParams The resulting {@link LaunchParams} after all calculations.
* @return A {@link Result} representing the result of the
* {@link LaunchParams} calculation.
*/
@Result
int onCalculate(TaskRecord task, WindowLayout layout, ActivityRecord activity,
ActivityRecord source, ActivityOptions options, LaunchParams currentParams,
LaunchParams outParams);
}
}