Split OverviewState for IconRecents Go

Split common functionality in OverviewState so that it can be reused in
both implementations for IconRecents Go and non-Go.

Bug: 114136250
Test: Manual test NexusLauncher, Launcher3GoWithQuickstep
Test: Manual test IconRecentsGo (gets to recents screen w/o crashing)
Change-Id: Ibff5d3573b3b22dcdfda1b0662d4dd219d2e382f

go/quickstep/src/com/android/launcher3/uioverrides/OverviewState.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2019 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.launcher3.uioverrides;
+
+import static com.android.launcher3.LauncherAnimUtils.OVERVIEW_TRANSITION_MS;
+import static com.android.launcher3.anim.Interpolators.DEACCEL_2;
+
+import android.graphics.Rect;
+
+import com.android.launcher3.DeviceProfile;
+import com.android.launcher3.Launcher;
+import com.android.launcher3.LauncherState;
+import com.android.launcher3.R;
+import com.android.launcher3.userevent.nano.LauncherLogProto;
+import com.android.quickstep.RecentsModel;
+
+/**
+ * Definition for overview state
+ */
+public class OverviewState extends LauncherState {
+
+    // TODO: Remove this when we refactor BackgroundAppState
+    protected static final Rect sTempRect = new Rect();
+
+    private static final int STATE_FLAGS = FLAG_WORKSPACE_ICONS_CAN_BE_DRAGGED
+            | FLAG_DISABLE_RESTORE | FLAG_OVERVIEW_UI | FLAG_DISABLE_ACCESSIBILITY;
+
+    public OverviewState(int id) {
+        this(id, OVERVIEW_TRANSITION_MS, STATE_FLAGS);
+    }
+
+    protected OverviewState(int id, int transitionDuration, int stateFlags) {
+        super(id, LauncherLogProto.ContainerType.TASKSWITCHER, transitionDuration, stateFlags);
+    }
+
+    @Override
+    public float[] getOverviewScaleAndTranslationYFactor(Launcher launcher) {
+        return new float[] {1f, 0f};
+    }
+
+    @Override
+    public void onStateDisabled(Launcher launcher) {
+        RecentsModel.INSTANCE.get(launcher).resetAssistCache();
+    }
+
+    @Override
+    public PageAlphaProvider getWorkspacePageAlphaProvider(Launcher launcher) {
+        return new PageAlphaProvider(DEACCEL_2) {
+            @Override
+            public float getPageAlpha(int pageIndex) {
+                return 0;
+            }
+        };
+    }
+
+    @Override
+    public int getVisibleElements(Launcher launcher) {
+        return NONE;
+    }
+
+    @Override
+    public float getWorkspaceScrimAlpha(Launcher launcher) {
+        return 0.5f;
+    }
+
+    @Override
+    public String getDescription(Launcher launcher) {
+        return launcher.getString(R.string.accessibility_desc_recent_apps);
+    }
+
+    @Override
+    public void onBackPressed(Launcher launcher) {
+        // TODO: Add logic to go back to task if coming from a currently running task.
+        super.onBackPressed(launcher);
+    }
+
+
+    public static float getDefaultSwipeHeight(Launcher launcher) {
+        DeviceProfile dp = launcher.getDeviceProfile();
+        return dp.allAppsCellHeightPx - dp.allAppsIconTextSizePx;
+    }
+}