content: /*
   * Copyright (C) 2015 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.wm;
  
  import static android.app.WindowConfiguration.WINDOWING_MODE_FREEFORM;
  import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN;
  import static android.app.WindowConfiguration.WINDOWING_MODE_PINNED;
  import static android.app.WindowConfiguration.WINDOWING_MODE_UNDEFINED;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_LOCKED;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_NOSENSOR;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_PORTRAIT;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_REVERSE_PORTRAIT;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_SENSOR_LANDSCAPE;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_USER_LANDSCAPE;
  import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_USER_PORTRAIT;
  import static android.util.DisplayMetrics.DENSITY_DEFAULT;
  import static android.view.Display.DEFAULT_DISPLAY;
  import static android.view.Display.INVALID_DISPLAY;
  
  import static com.android.server.wm.ActivityTaskManagerDebugConfig.TAG_ATM;
  import static com.android.server.wm.ActivityTaskManagerDebugConfig.TAG_WITH_CLASS_NAME;
  
  import android.annotation.NonNull;
  import android.annotation.Nullable;
  import android.app.ActivityOptions;
  import android.app.WindowConfiguration;
  import android.content.pm.ActivityInfo;
  import android.content.pm.ApplicationInfo;
  import android.content.res.Configuration;
  import android.graphics.Rect;
  import android.os.Build;
  import android.util.Slog;
  import android.view.Gravity;
  import android.view.View;
  
  import com.android.internal.annotations.VisibleForTesting;
  import com.android.server.wm.LaunchParamsController.LaunchParams;
  import com.android.server.wm.LaunchParamsController.LaunchParamsModifier;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * The class that defines the default launch params for tasks.
   */
  class TaskLaunchParamsModifier implements LaunchParamsModifier {
      private static final String TAG = TAG_WITH_CLASS_NAME ? "TaskLaunchParamsModifier" : TAG_ATM;
      private static final boolean DEBUG = false;
  
      // A mask for SUPPORTS_SCREEN that indicates the activity supports resize.
      private static final int SUPPORTS_SCREEN_RESIZEABLE_MASK =
              ApplicationInfo.FLAG_SUPPORTS_SCREEN_DENSITIES
                      | ApplicationInfo.FLAG_SUPPORTS_LARGE_SCREENS
                      | ApplicationInfo.FLAG_SUPPORTS_SMALL_SCREENS
                      | ApplicationInfo.FLAG_RESIZEABLE_FOR_SCREENS
                      | ApplicationInfo.FLAG_SUPPORTS_SCREEN_DENSITIES
                      | ApplicationInfo.FLAG_SUPPORTS_XLARGE_SCREENS;
  
      // Screen size of Nexus 5x
      private static final int DEFAULT_PORTRAIT_PHONE_WIDTH_DP = 412;
      private static final int DEFAULT_PORTRAIT_PHONE_HEIGHT_DP = 732;
  
      // Allowance of size matching.
      private static final int EPSILON = 2;
  
      // Cascade window offset.
      private static final int CASCADING_OFFSET_DP = 75;
  
      // Threshold how close window corners have to be to call them colliding.
      private static final int BOUNDS_CONFLICT_THRESHOLD = 4;
  
      // Divide display size by this number to get each step to adjust bounds to avoid conflict.
      private static final int STEP_DENOMINATOR = 16;
  
      // We always want to step by at least this.
      private static final int MINIMAL_STEP = 1;
  
      private final ActivityStackSupervisor mSupervisor;
      private final Rect mTmpBounds = new Rect();
      private final int[] mTmpDirections = new int[2];
  
      private StringBuilder mLogBuilder;
  
      TaskLaunchParamsModifier(ActivityStackSupervisor supervisor) {
          mSupervisor = supervisor;
      }
  
      @VisibleForTesting
      int onCalculate(TaskRecord task, ActivityInfo.WindowLayout layout, ActivityRecord activity,
              ActivityRecord source, ActivityOptions options, LaunchParams currentParams,
              LaunchParams outParams) {
          return onCalculate(task, layout, activity, source, options, PHASE_BOUNDS, currentParams,
                  outParams);
      }
  
      @Override
      public int onCalculate(TaskRecord task, ActivityInfo.WindowLayout layout,
                             ActivityRecord activity, ActivityRecord source, ActivityOptions options,
                             int phase, LaunchParams currentParams, LaunchParams outParams) {
          initLogBuilder(task, activity);
          final int result = calculate(task, layout, activity, source, options, phase, currentParams,
                  outParams);
          outputLog();
          return result;
      }
  
      private int calculate(TaskRecord task, ActivityInfo.WindowLayout layout,
              ActivityRecord activity, ActivityRecord source, ActivityOptions options, int phase,
              LaunchParams currentParams, LaunchParams outParams) {
          final ActivityRecord root;
          if (task != null) {
              root = task.getRootActivity() == null ? activity : task.getRootActivity();
          } else {
              root = activity;
          }
  
          // TODO: Investigate whether we can safely ignore all cases where we don't have root
          // activity available. Note we can't know if the bounds are valid if we're not sure of the
          // requested orientation of the root activity. Therefore if we found such a case we may need
          // to pass the activity into this modifier in that case.
          if (root == null) {
              // There is a case that can lead us here. The caller is moving the top activity that is
              // in a task that has multiple activities to PIP mode. For that the caller is creating a
              // new task to host the activity so that we only move the top activity to PIP mode and
              // keep other activities in the previous task. There is no point to apply the launch
              // logic in this case.
              return RESULT_SKIP;
          }
  
          // STEP 1: Determine the display to launch the activity/task.
          final int displayId = getPreferredLaunchDisplay(task, options, source, currentParams);
          outParams.mPreferredDisplayId = displayId;
          ActivityDisplay display = mSupervisor.mRootActivityContainer.getActivityDisplay(displayId);
          if (DEBUG) {
              appendLog("display-id=" + outParams.mPreferredDisplayId + " display-windowing-mode="
                      + display.getWindowingMode());
          }
  
          if (phase == PHASE_DISPLAY) {
              return RESULT_CONTINUE;
          }
  
          // STEP 2: Resolve launch windowing mode.
          // STEP 2.1: Determine if any parameter has specified initial bounds. That might be the
          // launch bounds from activity options, or size/gravity passed in layout. It also treats the
          // launch windowing mode in options as a suggestion for future resolution.
          int launchMode = options != null ? options.getLaunchWindowingMode()
                  : WINDOWING_MODE_UNDEFINED;
          // hasInitialBounds is set if either activity options or layout has specified bounds. If
          // that's set we'll skip some adjustments later to avoid overriding the initial bounds.
          boolean hasInitialBounds = false;
          final boolean canApplyFreeformPolicy = canApplyFreeformWindowPolicy(display, launchMode);
          if (mSupervisor.canUseActivityOptionsLaunchBounds(options)
                  && (canApplyFreeformPolicy || canApplyPipWindowPolicy(launchMode))) {
              hasInitialBounds = true;
              launchMode = launchMode == WINDOWING_MODE_UNDEFINED
                      ? WINDOWING_MODE_FREEFORM
                      : launchMode;
              outParams.mBounds.set(options.getLaunchBounds());
              if (DEBUG) appendLog("activity-options-bounds=" + outParams.mBounds);
          } else if (launchMode == WINDOWING_MODE_PINNED) {
              // System controls PIP window's bounds, so don't apply launch bounds.
              if (DEBUG) appendLog("empty-window-layout-for-pip");
          } else if (launchMode == WINDOWING_MODE_FULLSCREEN) {
              if (DEBUG) appendLog("activity-options-fullscreen=" + outParams.mBounds);
          } else if (layout != null && canApplyFreeformPolicy) {
              getLayoutBounds(display, root, layout, mTmpBounds);
              if (!mTmpBounds.isEmpty()) {
                  launchMode = WINDOWING_MODE_FREEFORM;
                  outParams.mBounds.set(mTmpBounds);
                  hasInitialBounds = true;
                  if (DEBUG) appendLog("bounds-from-layout=" + outParams.mBounds);
              } else {
                  if (DEBUG) appendLog("empty-window-layout");
              }
          }
  
          // STEP 2.2: Check if previous modifier or the controller (referred as "callers" below) has
          // some opinions on launch mode and launch bounds. If they have opinions and there is no
          // initial bounds set in parameters. Note the check on display ID is also input param
          // related because we always defer to callers' suggestion if there is no specific display ID
          // in options or from source activity.
          //
          // If opinions from callers don't need any further resolution, we try to honor that as is as
          // much as possible later.
  
          // Flag to indicate if current param needs no further resolution. It's true it current
          // param isn't freeform mode, or it already has launch bounds.
          boolean fullyResolvedCurrentParam = false;
          // We inherit launch params from previous modifiers or LaunchParamsController if options,
          // layout and display conditions are not contradictory to their suggestions. It's important
          // to carry over their values because LaunchParamsController doesn't automatically do that.
          if (!currentParams.isEmpty() && !hasInitialBounds
                  && (!currentParams.hasPreferredDisplay()
                      || displayId == currentParams.mPreferredDisplayId)) {
              if (currentParams.hasWindowingMode()) {
                  launchMode = currentParams.mWindowingMode;
                  fullyResolvedCurrentParam = launchMode != WINDOWING_MODE_FREEFORM;
                  if (DEBUG) {
                      appendLog("inherit-" + WindowConfiguration.windowingModeToString(launchMode));
                  }
              }
  
              if (!currentParams.mBounds.isEmpty()) {
                  // Carry over bounds from callers regardless of launch mode because bounds is still
                  // used to restore last non-fullscreen bounds when launch mode is not freeform.
                  // Therefore it's not a resolution step for non-freeform launch mode and only
                  // consider it fully resolved only when launch mode is freeform.
                  outParams.mBounds.set(currentParams.mBounds);
                  if (launchMode == WINDOWING_MODE_FREEFORM) {
                      fullyResolvedCurrentParam = true;
                      if (DEBUG) appendLog("inherit-bounds=" + outParams.mBounds);
                  }
              }
          }
  
          // STEP 2.3: Adjust launch parameters as needed for freeform display. We enforce the policy
          // that legacy (pre-D) apps and those apps that can't handle multiple screen density well
          // are forced to be maximized. The rest of this step is to define the default policy when
          // there is no initial bounds or a fully resolved current params from callers.
          if (display.inFreeformWindowingMode()) {
              if (launchMode == WINDOWING_MODE_PINNED) {
                  if (DEBUG) appendLog("picture-in-picture");
              } else if (isTaskForcedMaximized(root)) {
                  // We're launching an activity that probably can't handle resizing nicely, so force
                  // it to be maximized even someone suggests launching it in freeform using launch
                  // options.
                  launchMode = WINDOWING_MODE_FULLSCREEN;
                  outParams.mBounds.setEmpty();
                  if (DEBUG) appendLog("forced-maximize");
              }
          } else {
              if (DEBUG) appendLog("non-freeform-display");
          }
          // If launch mode matches display windowing mode, let it inherit from display.
          outParams.mWindowingMode = launchMode == display.getWindowingMode()
                  ? WINDOWING_MODE_UNDEFINED : launchMode;
  
          if (phase == PHASE_WINDOWING_MODE) {
              return RESULT_CONTINUE;
          }
  
          // STEP 3: Determine final launch bounds based on resolved windowing mode and activity
          // requested orientation. We set bounds to empty for fullscreen mode and keep bounds as is
          // for all other windowing modes that's not freeform mode. One can read comments in
          // relevant methods to further understand this step.
          //
          // We skip making adjustments if the params are fully resolved from previous results.
          final int resolvedMode = (launchMode != WINDOWING_MODE_UNDEFINED) ? launchMode
                  : display.getWindowingMode();
          if (fullyResolvedCurrentParam) {
              if (resolvedMode == WINDOWING_MODE_FREEFORM) {
                  // Make sure bounds are in the display if it's possibly in a different display.
                  if (currentParams.mPreferredDisplayId != displayId) {
                      adjustBoundsToFitInDisplay(display, outParams.mBounds);
                  }
                  // Even though we want to keep original bounds, we still don't want it to stomp on
                  // an existing task.
                  adjustBoundsToAvoidConflictInDisplay(display, outParams.mBounds);
              }
          } else {
              if (source != null && source.inFreeformWindowingMode()
                      && resolvedMode == WINDOWING_MODE_FREEFORM
                      && outParams.mBounds.isEmpty()
                      && source.getDisplayId() == display.mDisplayId) {
                  // Set bounds to be not very far from source activity.
                  cascadeBounds(source.getBounds(), display, outParams.mBounds);
              }
              getTaskBounds(root, display, layout, resolvedMode, hasInitialBounds, outParams.mBounds);
          }
  
          return RESULT_CONTINUE;
      }
  
      private int getPreferredLaunchDisplay(@Nullable TaskRecord task,
              @Nullable ActivityOptions options, ActivityRecord source, LaunchParams currentParams) {
          if (!mSupervisor.mService.mSupportsMultiDisplay) {
              return DEFAULT_DISPLAY;
          }
  
          int displayId = INVALID_DISPLAY;
          final int optionLaunchId = options != null ? options.getLaunchDisplayId() : INVALID_DISPLAY;
          if (optionLaunchId != INVALID_DISPLAY) {
              if (DEBUG) appendLog("display-from-option=" + optionLaunchId);
              displayId = optionLaunchId;
          }
  
          // If the source activity is a no-display activity, pass on the launch display id from
          // source activity as currently preferred.
          if (displayId == INVALID_DISPLAY && source != null && source.noDisplay) {
              displayId = source.mHandoverLaunchDisplayId;
              if (DEBUG) appendLog("display-from-no-display-source=" + displayId);
          }
  
          ActivityStack stack =
                  (displayId == INVALID_DISPLAY && task != null) ? task.getStack() : null;
          if (stack != null) {
              if (DEBUG) appendLog("display-from-task=" + stack.mDisplayId);
              displayId = stack.mDisplayId;
          }
  
          if (displayId == INVALID_DISPLAY && source != null) {
              final int sourceDisplayId = source.getDisplayId();
              if (DEBUG) appendLog("display-from-source=" + sourceDisplayId);
              displayId = sourceDisplayId;
          }
  
          if (displayId != INVALID_DISPLAY
                  && mSupervisor.mRootActivityContainer.getActivityDisplay(displayId) == null) {
              displayId = currentParams.mPreferredDisplayId;
          }
          displayId = (displayId == INVALID_DISPLAY) ? currentParams.mPreferredDisplayId : displayId;
  
          return (displayId != INVALID_DISPLAY
                  && mSupervisor.mRootActivityContainer.getActivityDisplay(displayId) != null)
                  ? displayId : DEFAULT_DISPLAY;
      }
  
      private boolean canApplyFreeformWindowPolicy(@NonNull ActivityDisplay display, int launchMode) {
          return mSupervisor.mService.mSupportsFreeformWindowManagement
                  && (display.inFreeformWindowingMode() || launchMode == WINDOWING_MODE_FREEFORM);
      }
  
      private boolean canApplyPipWindowPolicy(int launchMode) {
          return mSupervisor.mService.mSupportsPictureInPicture
                  && launchMode == WINDOWING_MODE_PINNED;
      }
  
      private void getLayoutBounds(@NonNull ActivityDisplay display, @NonNull ActivityRecord root,
              @NonNull ActivityInfo.WindowLayout windowLayout, @NonNull Rect outBounds) {
          final int verticalGravity = windowLayout.gravity & Gravity.VERTICAL_GRAVITY_MASK;
          final int horizontalGravity = windowLayout.gravity & Gravity.HORIZONTAL_GRAVITY_MASK;
          if (!windowLayout.hasSpecifiedSize() && verticalGravity == 0 && horizontalGravity == 0) {
              outBounds.setEmpty();
              return;
          }
  
          final Rect bounds = display.getBounds();
          final int defaultWidth = bounds.width();
          final int defaultHeight = bounds.height();
  
          int width;
          int height;
          if (!windowLayout.hasSpecifiedSize()) {
              outBounds.setEmpty();
              getTaskBounds(root, display, windowLayout, WINDOWING_MODE_FREEFORM,
                      /* hasInitialBounds */ false, outBounds);
              width = outBounds.width();
              height = outBounds.height();
          } else {
              width = defaultWidth;
              if (windowLayout.width > 0 && windowLayout.width < defaultWidth) {
                  width = windowLayout.width;
              } else if (windowLayout.widthFraction > 0 && windowLayout.widthFraction < 1.0f) {
                  width = (int) (width * windowLayout.widthFraction);
              }
  
              height = defaultHeight;
              if (windowLayout.height > 0 && windowLayout.height < defaultHeight) {
                  height = windowLayout.height;
              } else if (windowLayout.heightFraction > 0 && windowLayout.heightFraction < 1.0f) {
                  height = (int) (height * windowLayout.heightFraction);
              }
          }
  
          final float fractionOfHorizontalOffset;
          switch (horizontalGravity) {
              case Gravity.LEFT:
                  fractionOfHorizontalOffset = 0f;
                  break;
              case Gravity.RIGHT:
                  fractionOfHorizontalOffset = 1f;
                  break;
              default:
                  fractionOfHorizontalOffset = 0.5f;
          }
  
          final float fractionOfVerticalOffset;
          switch (verticalGravity) {
              case Gravity.TOP:
                  fractionOfVerticalOffset = 0f;
                  break;
              case Gravity.BOTTOM:
                  fractionOfVerticalOffset = 1f;
                  break;
              default:
                  fractionOfVerticalOffset = 0.5f;
          }
  
          outBounds.set(0, 0, width, height);
          final int xOffset = (int) (fractionOfHorizontalOffset * (defaultWidth - width));
          final int yOffset = (int) (fractionOfVerticalOffset * (defaultHeight - height));
          outBounds.offset(xOffset, yOffset);
      }
  
      /**
       * Returns if task is forced to maximize.
       *
       * There are several cases where we force a task to maximize:
       * 1) Root activity is targeting pre-Donut, which by default can't handle multiple screen
       *    densities, so resizing will likely cause issues;
       * 2) Root activity doesn't declare any flag that it supports any screen density, so resizing
       *    may also cause issues;
       * 3) Root activity is not resizeable, for which we shouldn't allow user resize it.
       *
       * @param root the root activity to check against.
       * @return {@code true} if it should be forced to maximize; {@code false} otherwise.
       */
      private boolean isTaskForcedMaximized(@NonNull ActivityRecord root) {
          if (root.appInfo.targetSdkVersion < Build.VERSION_CODES.DONUT
                  || (root.appInfo.flags & SUPPORTS_SCREEN_RESIZEABLE_MASK) == 0) {
              return true;
          }
  
          return !root.isResizeable();
      }
  
      /**
       * Resolves activity requested orientation to 4 categories:
       * 1) {@link ActivityInfo#SCREEN_ORIENTATION_LOCKED} indicating app wants to lock down
       *    orientation;
       * 2) {@link ActivityInfo#SCREEN_ORIENTATION_LANDSCAPE} indicating app wants to be in landscape;
       * 3) {@link ActivityInfo#SCREEN_ORIENTATION_PORTRAIT} indicating app wants to be in portrait;
       * 4) {@link ActivityInfo#SCREEN_ORIENTATION_UNSPECIFIED} indicating app can handle any
       *    orientation.
       *
       * @param activity the activity to check
       * @return corresponding resolved orientation value.
       */
      private int resolveOrientation(@NonNull ActivityRecord activity) {
          int orientation = activity.info.screenOrientation;
          switch (orientation) {
              case SCREEN_ORIENTATION_NOSENSOR:
              case SCREEN_ORIENTATION_LOCKED:
                  orientation = SCREEN_ORIENTATION_LOCKED;
                  break;
              case SCREEN_ORIENTATION_SENSOR_LANDSCAPE:
              case SCREEN_ORIENTATION_REVERSE_LANDSCAPE:
              case SCREEN_ORIENTATION_USER_LANDSCAPE:
              case SCREEN_ORIENTATION_LANDSCAPE:
                  if (DEBUG) appendLog("activity-requested-landscape");
                  orientation = SCREEN_ORIENTATION_LANDSCAPE;
                  break;
              case SCREEN_ORIENTATION_SENSOR_PORTRAIT:
              case SCREEN_ORIENTATION_REVERSE_PORTRAIT:
              case SCREEN_ORIENTATION_USER_PORTRAIT:
              case SCREEN_ORIENTATION_PORTRAIT:
                  if (DEBUG) appendLog("activity-requested-portrait");
                  orientation = SCREEN_ORIENTATION_PORTRAIT;
                  break;
              default:
                  orientation = SCREEN_ORIENTATION_UNSPECIFIED;
          }
  
          return orientation;
      }
  
      private void cascadeBounds(@NonNull Rect srcBounds, @NonNull ActivityDisplay display,
              @NonNull Rect outBounds) {
          outBounds.set(srcBounds);
          float density = (float) display.getConfiguration().densityDpi / DENSITY_DEFAULT;
          final int defaultOffset = (int) (CASCADING_OFFSET_DP * density + 0.5f);
  
          display.getBounds(mTmpBounds);
          final int dx = Math.min(defaultOffset, Math.max(0, mTmpBounds.right - srcBounds.right));
          final int dy = Math.min(defaultOffset, Math.max(0, mTmpBounds.bottom - srcBounds.bottom));
          outBounds.offset(dx, dy);
      }
  
      private void getTaskBounds(@NonNull ActivityRecord root, @NonNull ActivityDisplay display,
              @NonNull ActivityInfo.WindowLayout layout, int resolvedMode, boolean hasInitialBounds,
              @NonNull Rect inOutBounds) {
          if (resolvedMode == WINDOWING_MODE_FULLSCREEN) {
              // We don't handle letterboxing here. Letterboxing will be handled by valid checks
              // later.
              inOutBounds.setEmpty();
              if (DEBUG) appendLog("maximized-bounds");
              return;
          }
  
          if (resolvedMode != WINDOWING_MODE_FREEFORM) {
              // We don't apply freeform bounds adjustment to other windowing modes.
              if (DEBUG) {
                  appendLog("skip-bounds-" + WindowConfiguration.windowingModeToString(resolvedMode));
              }
              return;
          }
  
          final int orientation = resolveOrientation(root, display, inOutBounds);
          if (orientation != SCREEN_ORIENTATION_PORTRAIT
                  && orientation != SCREEN_ORIENTATION_LANDSCAPE) {
              throw new IllegalStateException(
                      "Orientation must be one of portrait or landscape, but it's "
                      + ActivityInfo.screenOrientationToString(orientation));
          }
  
          // First we get the default size we want.
          getDefaultFreeformSize(display, layout, orientation, mTmpBounds);
          if (hasInitialBounds || sizeMatches(inOutBounds, mTmpBounds)) {
              // We're here because either input parameters specified initial bounds, or the suggested
              // bounds have the same size of the default freeform size. We should use the suggested
              // bounds if possible -- so if app can handle the orientation we just use it, and if not
              // we transpose the suggested bounds in-place.
              if (orientation == orientationFromBounds(inOutBounds)) {
                  if (DEBUG) appendLog("freeform-size-orientation-match=" + inOutBounds);
              } else {
                  // Meh, orientation doesn't match. Let's rotate inOutBounds in-place.
                  centerBounds(display, inOutBounds.height(), inOutBounds.width(), inOutBounds);
                  if (DEBUG) appendLog("freeform-orientation-mismatch=" + inOutBounds);
              }
          } else {
              // We are here either because there is no suggested bounds, or the suggested bounds is
              // a cascade from source activity. We should use the default freeform size and center it
              // to the center of suggested bounds (or the display if no suggested bounds). The
              // default size might be too big to center to source activity bounds in display, so we
              // may need to move it back to the display.
              centerBounds(display, mTmpBounds.width(), mTmpBounds.height(), inOutBounds);
              adjustBoundsToFitInDisplay(display, inOutBounds);
              if (DEBUG) appendLog("freeform-size-mismatch=" + inOutBounds);
          }
  
          // Lastly we adjust bounds to avoid conflicts with other tasks as much as possible.
          adjustBoundsToAvoidConflictInDisplay(display, inOutBounds);
      }
  
      private int convertOrientationToScreenOrientation(int orientation) {
          switch (orientation) {
              case Configuration.ORIENTATION_LANDSCAPE:
                  return SCREEN_ORIENTATION_LANDSCAPE;
              case Configuration.ORIENTATION_PORTRAIT:
                  return SCREEN_ORIENTATION_PORTRAIT;
              default:
                  return SCREEN_ORIENTATION_UNSPECIFIED;
          }
      }
  
      private int resolveOrientation(@NonNull ActivityRecord root, @NonNull ActivityDisplay display,
              @NonNull Rect bounds) {
          int orientation = resolveOrientation(root);
  
          if (orientation == SCREEN_ORIENTATION_LOCKED) {
              orientation = bounds.isEmpty()
                      ? convertOrientationToScreenOrientation(display.getConfiguration().orientation)
                      : orientationFromBounds(bounds);
              if (DEBUG) {
                  appendLog(bounds.isEmpty() ? "locked-orientation-from-display=" + orientation
                          : "locked-orientation-from-bounds=" + bounds);
              }
          }
  
          if (orientation == SCREEN_ORIENTATION_UNSPECIFIED) {
              orientation = bounds.isEmpty() ? SCREEN_ORIENTATION_PORTRAIT
                      : orientationFromBounds(bounds);
              if (DEBUG) {
                  appendLog(bounds.isEmpty() ? "default-portrait"
                          : "orientation-from-bounds=" + bounds);
              }
          }
  
          return orientation;
      }
  
      private void getDefaultFreeformSize(@NonNull ActivityDisplay display,
              @NonNull ActivityInfo.WindowLayout layout, int orientation, @NonNull Rect bounds) {
          // Default size, which is letterboxing/pillarboxing in display. That's to say the large
          // dimension of default size is the small dimension of display size, and the small dimension
          // of default size is calculated to keep the same aspect ratio as the display's.
          Rect displayBounds = display.getBounds();
          final int portraitHeight = Math.min(displayBounds.width(), displayBounds.height());
          final int otherDimension = Math.max(displayBounds.width(), displayBounds.height());
          final int portraitWidth = (portraitHeight * portraitHeight) / otherDimension;
          final int defaultWidth = (orientation == SCREEN_ORIENTATION_LANDSCAPE) ? portraitHeight
                  : portraitWidth;
          final int defaultHeight = (orientation == SCREEN_ORIENTATION_LANDSCAPE) ? portraitWidth
                  : portraitHeight;
  
          // Get window size based on Nexus 5x screen, we assume that this is enough to show content
          // of activities.
          final float density = (float) display.getConfiguration().densityDpi / DENSITY_DEFAULT;
          final int phonePortraitWidth = (int) (DEFAULT_PORTRAIT_PHONE_WIDTH_DP * density + 0.5f);
          final int phonePortraitHeight = (int) (DEFAULT_PORTRAIT_PHONE_HEIGHT_DP * density + 0.5f);
          final int phoneWidth = (orientation == SCREEN_ORIENTATION_LANDSCAPE) ? phonePortraitHeight
                  : phonePortraitWidth;
          final int phoneHeight = (orientation == SCREEN_ORIENTATION_LANDSCAPE) ? phonePortraitWidth
                  : phonePortraitHeight;
  
          // Minimum layout requirements.
          final int layoutMinWidth = (layout == null) ? -1 : layout.minWidth;
          final int layoutMinHeight = (layout == null) ? -1 : layout.minHeight;
  
          // Final result.
          final int width = Math.min(defaultWidth, Math.max(phoneWidth, layoutMinWidth));
          final int height = Math.min(defaultHeight, Math.max(phoneHeight, layoutMinHeight));
  
          bounds.set(0, 0, width, height);
      }
  
      /**
       * Gets centered bounds of width x height. If inOutBounds is not empty, the result bounds
       * centers at its center or display's center if inOutBounds is empty.
       */
      private void centerBounds(@NonNull ActivityDisplay display, int width, int height,
              @NonNull Rect inOutBounds) {
          if (inOutBounds.isEmpty()) {
              display.getBounds(inOutBounds);
          }
          final int left = inOutBounds.centerX() - width / 2;
          final int top = inOutBounds.centerY() - height / 2;
          inOutBounds.set(left, top, left + width, top + height);
      }
  
      private void adjustBoundsToFitInDisplay(@NonNull ActivityDisplay display,
              @NonNull Rect inOutBounds) {
          final Rect displayBounds = display.getBounds();
  
          if (displayBounds.width() < inOutBounds.width()
                  || displayBounds.height() < inOutBounds.height()) {
              // There is no way for us to fit the bounds in the display without changing width
              // or height. Just move the start to align with the display.
              final int layoutDirection =
                      mSupervisor.mRootActivityContainer.getConfiguration().getLayoutDirection();
              final int left = layoutDirection == View.LAYOUT_DIRECTION_RTL
                      ? displayBounds.width() - inOutBounds.width()
                      : 0;
              inOutBounds.offsetTo(left, 0 /* newTop */);
              return;
          }
  
          final int dx;
          if (inOutBounds.right > displayBounds.right) {
              // Right edge is out of display.
              dx = displayBounds.right - inOutBounds.right;
          } else if (inOutBounds.left < displayBounds.left) {
              // Left edge is out of display.
              dx = displayBounds.left - inOutBounds.left;
          } else {
              // Vertical edges are all in display.
              dx = 0;
          }
  
          final int dy;
          if (inOutBounds.top < displayBounds.top) {
              // Top edge is out of display.
              dy = displayBounds.top - inOutBounds.top;
          } else if (inOutBounds.bottom > displayBounds.bottom) {
              // Bottom edge is out of display.
              dy = displayBounds.bottom - inOutBounds.bottom;
          } else {
              // Horizontal edges are all in display.
              dy = 0;
          }
          inOutBounds.offset(dx, dy);
      }
  
      /**
       * Adjusts input bounds to avoid conflict with existing tasks in the display.
       *
       * If the input bounds conflict with existing tasks, this method scans the bounds in a series of
       * directions to find a location where the we can put the bounds in display without conflict
       * with any other tasks.
       *
       * It doesn't try to adjust bounds that's not fully in the given display.
       *
       * @param display the display which tasks are to check
       * @param inOutBounds the bounds used to input initial bounds and output result bounds
       */
      private void adjustBoundsToAvoidConflictInDisplay(@NonNull ActivityDisplay display,
              @NonNull Rect inOutBounds) {
          final List<Rect> taskBoundsToCheck = new ArrayList<>();
          for (int i = 0; i < display.getChildCount(); ++i) {
              final ActivityStack stack = display.getChildAt(i);
              if (!stack.inFreeformWindowingMode()) {
                  continue;
              }
  
              for (int j = 0; j < stack.getChildCount(); ++j) {
                  taskBoundsToCheck.add(stack.getChildAt(j).getBounds());
              }
          }
          adjustBoundsToAvoidConflict(display.getBounds(), taskBoundsToCheck, inOutBounds);
      }
  
      /**
       * Adjusts input bounds to avoid conflict with provided display bounds and list of tasks bounds
       * for the display.
       *
       * Scans the bounds in directions to find a candidate location that does not conflict with the
       * provided list of task bounds. If starting bounds are outside the display bounds or if no
       * suitable candidate bounds are found, the method returns the input bounds.
       *
       * @param displayBounds display bounds used to restrict the candidate bounds
       * @param taskBoundsToCheck list of task bounds to check for conflict
       * @param inOutBounds the bounds used to input initial bounds and output result bounds
       */
      @VisibleForTesting
      void adjustBoundsToAvoidConflict(@NonNull Rect displayBounds,
              @NonNull List<Rect> taskBoundsToCheck,
              @NonNull Rect inOutBounds) {
          if (!displayBounds.contains(inOutBounds)) {
              // The initial bounds are already out of display. The scanning algorithm below doesn't
              // work so well with them.
              return;
          }
  
          if (!boundsConflict(taskBoundsToCheck, inOutBounds)) {
              // Current proposal doesn't conflict with any task. Early return to avoid unnecessary
              // calculation.
              return;
          }
  
          calculateCandidateShiftDirections(displayBounds, inOutBounds);
          for (int direction : mTmpDirections) {
              if (direction == Gravity.NO_GRAVITY) {
                  // We exhausted candidate directions, give up.
                  break;
              }
  
              mTmpBounds.set(inOutBounds);
              while (boundsConflict(taskBoundsToCheck, mTmpBounds)
                      && displayBounds.contains(mTmpBounds)) {
                  shiftBounds(direction, displayBounds, mTmpBounds);
              }
  
              if (!boundsConflict(taskBoundsToCheck, mTmpBounds)
                      && displayBounds.contains(mTmpBounds)) {
                  // Found a candidate. Just use this.
                  inOutBounds.set(mTmpBounds);
                  if (DEBUG) appendLog("avoid-bounds-conflict=" + inOutBounds);
                  return;
              }
  
              // Didn't find a conflict free bounds here. Try the next candidate direction.
          }
  
          // We failed to find a conflict free location. Just keep the original result.
      }
  
      /**
       * Determines scanning directions and their priorities to avoid bounds conflict.
       *
       * @param availableBounds bounds that the result must be in
       * @param initialBounds initial bounds when start scanning
       */
      private void calculateCandidateShiftDirections(@NonNull Rect availableBounds,
              @NonNull Rect initialBounds) {
          for (int i = 0; i < mTmpDirections.length; ++i) {
              mTmpDirections[i] = Gravity.NO_GRAVITY;
          }
  
          final int oneThirdWidth = (2 * availableBounds.left + availableBounds.right) / 3;
          final int twoThirdWidth = (availableBounds.left + 2 * availableBounds.right) / 3;
          final int centerX = initialBounds.centerX();
          if (centerX < oneThirdWidth) {
              // Too close to left, just scan to the right.
              mTmpDirections[0] = Gravity.RIGHT;
              return;
          } else if (centerX > twoThirdWidth) {
              // Too close to right, just scan to the left.
              mTmpDirections[0] = Gravity.LEFT;
              return;
          }
  
          final int oneThirdHeight = (2 * availableBounds.top + availableBounds.bottom) / 3;
          final int twoThirdHeight = (availableBounds.top + 2 * availableBounds.bottom) / 3;
          final int centerY = initialBounds.centerY();
          if (centerY < oneThirdHeight || centerY > twoThirdHeight) {
              // Too close to top or bottom boundary and we're in the middle horizontally, scan
              // horizontally in both directions.
              mTmpDirections[0] = Gravity.RIGHT;
              mTmpDirections[1] = Gravity.LEFT;
              return;
          }
  
          // We're in the center region both horizontally and vertically. Scan in both directions of
          // primary diagonal.
          mTmpDirections[0] = Gravity.BOTTOM | Gravity.RIGHT;
          mTmpDirections[1] = Gravity.TOP | Gravity.LEFT;
      }
  
      private boolean boundsConflict(@NonNull List<Rect> taskBoundsToCheck,
                                     @NonNull Rect candidateBounds) {
          for (Rect taskBounds : taskBoundsToCheck) {
              final boolean leftClose = Math.abs(taskBounds.left - candidateBounds.left)
                      < BOUNDS_CONFLICT_THRESHOLD;
              final boolean topClose = Math.abs(taskBounds.top - candidateBounds.top)
                      < BOUNDS_CONFLICT_THRESHOLD;
              final boolean rightClose = Math.abs(taskBounds.right - candidateBounds.right)
                      < BOUNDS_CONFLICT_THRESHOLD;
              final boolean bottomClose = Math.abs(taskBounds.bottom - candidateBounds.bottom)
                      < BOUNDS_CONFLICT_THRESHOLD;
  
              if ((leftClose && topClose) || (leftClose && bottomClose) || (rightClose && topClose)
                      || (rightClose && bottomClose)) {
                  return true;
              }
          }
  
          return false;
      }
  
      private void shiftBounds(int direction, @NonNull Rect availableRect,
              @NonNull Rect inOutBounds) {
          final int horizontalOffset;
          switch (direction & Gravity.HORIZONTAL_GRAVITY_MASK) {
              case Gravity.LEFT:
                  horizontalOffset = -Math.max(MINIMAL_STEP,
                          availableRect.width() / STEP_DENOMINATOR);
                  break;
              case Gravity.RIGHT:
                  horizontalOffset = Math.max(MINIMAL_STEP, availableRect.width() / STEP_DENOMINATOR);
                  break;
              default:
                  horizontalOffset = 0;
          }
  
          final int verticalOffset;
          switch (direction & Gravity.VERTICAL_GRAVITY_MASK) {
              case Gravity.TOP:
                  verticalOffset = -Math.max(MINIMAL_STEP, availableRect.height() / STEP_DENOMINATOR);
                  break;
              case Gravity.BOTTOM:
                  verticalOffset = Math.max(MINIMAL_STEP, availableRect.height() / STEP_DENOMINATOR);
                  break;
              default:
                  verticalOffset = 0;
          }
  
          inOutBounds.offset(horizontalOffset, verticalOffset);
      }
  
      private void initLogBuilder(TaskRecord task, ActivityRecord activity) {
          if (DEBUG) {
              mLogBuilder = new StringBuilder("TaskLaunchParamsModifier:task=" + task
                      + " activity=" + activity);
          }
      }
  
      private void appendLog(String log) {
          if (DEBUG) mLogBuilder.append(" ").append(log);
      }
  
      private void outputLog() {
          if (DEBUG) Slog.d(TAG, mLogBuilder.toString());
      }
  
      private static int orientationFromBounds(Rect bounds) {
          return bounds.width() > bounds.height() ? SCREEN_ORIENTATION_LANDSCAPE
                  : SCREEN_ORIENTATION_PORTRAIT;
      }
  
      private static boolean sizeMatches(Rect left, Rect right) {
          return (Math.abs(right.width() - left.width()) < EPSILON)
                  && (Math.abs(right.height() - left.height()) < EPSILON);
      }
  }
  