Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/widget/emptybackground/EmptyBackgroundViewWrapper.java

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.widget.emptybackground;
+
+import android.app.Activity;
+import android.view.View;
+import android.view.View.OnAttachStateChangeListener;
+import android.view.ViewStub;
+
+import com.google.android.apps.chrome.R;
+
+import org.chromium.chrome.browser.Tab;
+import org.chromium.chrome.browser.appmenu.AppMenuHandler;
+import org.chromium.chrome.browser.compositor.layouts.OverviewModeBehavior;
+import org.chromium.chrome.browser.tabmodel.ChromeTabCreator;
+import org.chromium.chrome.browser.tabmodel.EmptyTabModelObserver;
+import org.chromium.chrome.browser.tabmodel.EmptyTabModelSelectorObserver;
+import org.chromium.chrome.browser.tabmodel.TabModel;
+import org.chromium.chrome.browser.tabmodel.TabModel.TabLaunchType;
+import org.chromium.chrome.browser.tabmodel.TabModelObserver;
+import org.chromium.chrome.browser.tabmodel.TabModelSelector;
+import org.chromium.chrome.browser.tabmodel.TabModelSelectorObserver;
+
+import java.util.List;
+
+/**
+ * Handler for {@link EmptyBackgroundViewTablet}.
+ */
+public class EmptyBackgroundViewWrapper {
+    private final Activity mActivity;
+    private final TabModelSelector mTabModelSelector;
+    private final ChromeTabCreator mTabCreator;
+    private final TabModelObserver mTabModelObserver;
+    private final TabModelSelectorObserver mTabModelSelectorObserver;
+    private final OverviewModeBehavior mOverviewModeBehavior;
+
+    private EmptyBackgroundViewTablet mBackgroundView;
+    private final AppMenuHandler mMenuHandler;
+
+    /**
+     * Creates a {@link EmptyBackgroundViewWrapper} instance that will lazily inflate.
+     * @param selector             A {@link TabModelSelector} that will be used to query system
+     *                             state.
+     * @param tabCreator           A {@link ChromeTabCreator} that will be used to open the New Tab
+     *                             Page.
+     * @param activity             An {@link Activity} that represents a parent of the
+     *                             {@link android.view.ViewStub}.
+     * @param menuHandler          A {@link AppMenuHandler} to handle menu touch events.
+     * @param overviewModeBehavior A {@link OverviewModeBehavior} instance to detect when the app
+     *                             is in overview mode.
+     */
+    public EmptyBackgroundViewWrapper(TabModelSelector selector, ChromeTabCreator tabCreator,
+            Activity activity, AppMenuHandler menuHandler,
+            OverviewModeBehavior overviewModeBehavior) {
+        mActivity = activity;
+        mMenuHandler = menuHandler;
+        mTabModelSelector = selector;
+        mTabCreator = tabCreator;
+        mOverviewModeBehavior = overviewModeBehavior;
+        mTabModelObserver = new EmptyTabModelObserver() {
+            @Override
+            public void didAddTab(Tab tab, TabLaunchType type) {
+                updateEmptyContainerState();
+            }
+
+            @Override
+            public void tabClosureUndone(Tab tab) {
+                updateEmptyContainerState();
+            }
+
+            @Override
+            public void didCloseTab(Tab tab) {
+                updateEmptyContainerState();
+            }
+
+            @Override
+            public void tabPendingClosure(Tab tab) {
+                updateEmptyContainerState();
+            }
+
+            @Override
+            public void allTabsPendingClosure(List<Integer> tabIds) {
+                updateEmptyContainerState();
+            }
+        };
+        mTabModelSelectorObserver = new EmptyTabModelSelectorObserver() {
+            @Override
+            public void onTabModelSelected(TabModel newModel, TabModel oldModel) {
+                updateEmptyContainerState();
+            }
+        };
+    }
+
+    /**
+     * Initialize the wrapper to listen for the proper notifications.
+     */
+    public void initialize() {
+        for (TabModel model : mTabModelSelector.getModels()) model.addObserver(mTabModelObserver);
+        mTabModelSelector.addObserver(mTabModelSelectorObserver);
+    }
+
+    /**
+     * Unregister all dependencies and listeners.
+     */
+    public void uninitialize() {
+        for (TabModel model : mTabModelSelector.getModels()) {
+            model.removeObserver(mTabModelObserver);
+        }
+        mTabModelSelector.removeObserver(mTabModelSelectorObserver);
+    }
+
+    private void inflateViewIfNecessary() {
+        if (mBackgroundView != null) return;
+
+        mBackgroundView = (EmptyBackgroundViewTablet) ((ViewStub) mActivity.findViewById(
+                R.id.empty_container_stub)).inflate();
+        mBackgroundView.setTabModelSelector(mTabModelSelector);
+        mBackgroundView.setTabCreator(mTabCreator);
+        mBackgroundView.setMenuOnTouchListener(mMenuHandler);
+        mBackgroundView.addOnAttachStateChangeListener(new OnAttachStateChangeListener() {
+            @Override
+            public void onViewDetachedFromWindow(View v) {
+                uninitialize();
+            }
+
+            @Override
+            public void onViewAttachedToWindow(View v) {
+            }
+        });
+    }
+
+    private void updateEmptyContainerState() {
+        boolean showEmptyBackground = shouldShowEmptyContainer();
+        if (showEmptyBackground) {
+            inflateViewIfNecessary();
+        }
+
+        if (mBackgroundView != null) {
+            mBackgroundView.setEmptyContainerState(showEmptyBackground);
+        }
+    }
+
+    private boolean shouldShowEmptyContainer() {
+        TabModel model = mTabModelSelector.getModel(false);
+        if (model == null) {
+            return false;
+        }
+        boolean isIncognitoEmpty = mTabModelSelector.getModel(true).getCount() == 0;
+        boolean incognitoSelected = mTabModelSelector.isIncognitoSelected();
+
+        // Only show the empty container if:
+        // 1. There are no tabs in the normal TabModel AND
+        // 2. Overview mode is not showing AND
+        // 3. We're in the normal TabModel OR there are no tabs present in either model
+        return model.getCount() == 0 && !mOverviewModeBehavior.overviewVisible()
+                && (!incognitoSelected || isIncognitoEmpty);
+    }
+}