Add CollapsingToolbarLayout for sub settings

Settings app is planning to make toolbar collapsible for next
Android release. This CL is to add a new layout for
CollapsingToolbarLayout in the Settings app and to update the theme
correspondly. This feature will be controlled by feature flag, which
makes Settings app compacitible with the existing layout.

Bug: 174451673
Test: manul test and visual verification
1) Enable the feature and open Settings app
2) Navigate to each sub page and check if toolbar is collapsible

Change-Id: Ibef524bbaa7ae3f0a43db7e40e599f42e009437f
diff --git a/src/com/android/settings/SettingsActivity.java b/src/com/android/settings/SettingsActivity.java
index 1c2952a..7f214f6 100644
--- a/src/com/android/settings/SettingsActivity.java
+++ b/src/com/android/settings/SettingsActivity.java
@@ -288,7 +288,9 @@
         if (actionBar != null) {
             actionBar.setDisplayHomeAsUpEnabled(!isInSetupWizard);
             actionBar.setHomeButtonEnabled(!isInSetupWizard);
-            actionBar.setDisplayShowTitleEnabled(true);
+            // TODO(b/176882938): Enable title after material component updated
+            // If CollapsingToolbarLayout is applied, the old action bar won't show title.
+            actionBar.setDisplayShowTitleEnabled(mCollapsingToolbarLayout == null);
         }
         mSwitchBar = findViewById(R.id.switch_bar);
         if (mSwitchBar != null) {
diff --git a/src/com/android/settings/SettingsPreferenceFragment.java b/src/com/android/settings/SettingsPreferenceFragment.java
index 659ada4..2c628f6 100644
--- a/src/com/android/settings/SettingsPreferenceFragment.java
+++ b/src/com/android/settings/SettingsPreferenceFragment.java
@@ -26,6 +26,7 @@
 import android.os.Bundle;
 import android.text.TextUtils;
 import android.util.ArrayMap;
+import android.util.FeatureFlagUtils;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -42,6 +43,7 @@
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
 
+import com.android.settings.core.FeatureFlags;
 import com.android.settings.core.InstrumentedPreferenceFragment;
 import com.android.settings.core.instrumentation.InstrumentedDialogFragment;
 import com.android.settings.search.actionbar.SearchMenuController;
@@ -126,8 +128,11 @@
     @Override
     public void onCreate(Bundle icicle) {
         super.onCreate(icicle);
-        SearchMenuController.init(this /* host */);
-        HelpMenuController.init(this /* host */);
+        // TODO(b/176883483): Remove both search and help menu if this feature rolled out
+        if (!FeatureFlagUtils.isEnabled(getContext(), FeatureFlags.SILKY_HOME)) {
+            SearchMenuController.init(this /* host */);
+            HelpMenuController.init(this /* host */);
+        }
 
         if (icicle != null) {
             mPreferenceHighlighted = icicle.getBoolean(SAVE_HIGHLIGHTED_KEY);
diff --git a/src/com/android/settings/core/SettingsBaseActivity.java b/src/com/android/settings/core/SettingsBaseActivity.java
index d160dc5..4704702 100644
--- a/src/com/android/settings/core/SettingsBaseActivity.java
+++ b/src/com/android/settings/core/SettingsBaseActivity.java
@@ -29,6 +29,7 @@
 import android.os.Bundle;
 import android.text.TextUtils;
 import android.util.ArraySet;
+import android.util.FeatureFlagUtils;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -43,8 +44,11 @@
 import com.android.settings.dashboard.CategoryManager;
 import com.android.settingslib.drawer.Tile;
 
+import com.google.android.material.appbar.CollapsingToolbarLayout;
 import com.google.android.setupcompat.util.WizardManagerHelper;
 
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -55,6 +59,7 @@
     protected static final boolean DEBUG_TIMING = false;
     private static final String TAG = "SettingsBaseActivity";
     private static final String DATA_SCHEME_PKG = "package";
+    private static final int TOOLBAR_MAX_LINE_NUMBER = 2;
 
     // Serves as a temporary list of tiles to ignore until we heard back from the PM that they
     // are disabled.
@@ -62,6 +67,8 @@
 
     private final PackageReceiver mPackageReceiver = new PackageReceiver();
     private final List<CategoryListener> mCategoryListeners = new ArrayList<>();
+
+    protected CollapsingToolbarLayout mCollapsingToolbarLayout;
     private int mCategoriesUpdateTaskCount;
 
     @Override
@@ -79,21 +86,30 @@
             requestWindowFeature(Window.FEATURE_NO_TITLE);
         }
         // Apply SetupWizard light theme during setup flow. This is for SubSettings pages.
-        if (WizardManagerHelper.isAnySetupWizard(getIntent()) && this instanceof SubSettings) {
+        final boolean isAnySetupWizard = WizardManagerHelper.isAnySetupWizard(getIntent());
+        if (isAnySetupWizard && this instanceof SubSettings) {
             setTheme(R.style.LightTheme_SubSettings_SetupWizard);
         }
-        super.setContentView(R.layout.settings_base_layout);
 
+        if (FeatureFlagUtils.isEnabled(this, FeatureFlags.SILKY_HOME)
+                && isToolbarEnabled() && !isAnySetupWizard) {
+            super.setContentView(R.layout.settings_collapsing_base_layout);
+            mCollapsingToolbarLayout = findViewById(R.id.collapsing_toolbar);
+        } else {
+            super.setContentView(R.layout.settings_base_layout);
+        }
+
+        // This is to hide the toolbar from those pages which don't need a toolbar originally.
         final Toolbar toolbar = findViewById(R.id.action_bar);
-        if (theme.getBoolean(android.R.styleable.Theme_windowNoTitle, false)) {
+        if (!isToolbarEnabled() || isAnySetupWizard) {
             toolbar.setVisibility(View.GONE);
             return;
         }
         setActionBar(toolbar);
+        initCollapsingToolbar();
 
         if (DEBUG_TIMING) {
-            Log.d(TAG, "onCreate took " + (System.currentTimeMillis() - startTime)
-                    + " ms");
+            Log.d(TAG, "onCreate took " + (System.currentTimeMillis() - startTime) + " ms");
         }
     }
 
@@ -151,6 +167,70 @@
         ((ViewGroup) findViewById(R.id.content_frame)).addView(view, params);
     }
 
+    @Override
+    public void setTitle(CharSequence title) {
+        if (mCollapsingToolbarLayout != null) {
+            mCollapsingToolbarLayout.setTitle(title);
+        }
+        super.setTitle(title);
+    }
+
+    @Override
+    public void setTitle(int titleId) {
+        if (mCollapsingToolbarLayout != null) {
+            mCollapsingToolbarLayout.setTitle(getText(titleId));
+        }
+        super.setTitle(titleId);
+    }
+
+    /**
+     * SubSetting page should show a toolbar by default. If the page wouldn't show a toolbar,
+     * override this method and return false value.
+     * @return ture by default
+     */
+    protected boolean isToolbarEnabled() {
+        return true;
+    }
+
+    private void initCollapsingToolbar() {
+        if (mCollapsingToolbarLayout == null) {
+            return;
+        }
+        mCollapsingToolbarLayout.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
+            @Override
+            public void onLayoutChange(View v, int left, int top, int right, int bottom,
+                    int oldLeft, int oldTop, int oldRight, int oldBottom) {
+                v.removeOnLayoutChangeListener(this);
+                final int count = getLineCount();
+                if (count > TOOLBAR_MAX_LINE_NUMBER) {
+                    mCollapsingToolbarLayout
+                            .setExpandedTitleTextAppearance(R.style.ToolbarText_MoreThanTwoLines);
+                } else {
+                    mCollapsingToolbarLayout.setExpandedTitleTextAppearance(R.style.ToolbarText);
+                }
+            }
+        });
+    }
+
+    private int getLineCount() {
+        try {
+            final Class<?> toolbarClazz = mCollapsingToolbarLayout.getClass();
+            final Field textHelperField = toolbarClazz.getDeclaredField("collapsingTextHelper");
+            textHelperField.setAccessible(true);
+            final Object textHelperObj = textHelperField.get(mCollapsingToolbarLayout);
+
+            final Field layoutField = textHelperObj.getClass().getDeclaredField("textLayout");
+            layoutField.setAccessible(true);
+            final Object layoutObj = layoutField.get(textHelperObj);
+
+            final Method method = layoutObj.getClass().getDeclaredMethod("getLineCount");
+            return (int) method.invoke(layoutObj);
+        } catch (Exception e) {
+            return 0;
+        }
+    }
+
+
     private void onCategoriesChanged(Set<String> categories) {
         final int N = mCategoryListeners.size();
         for (int i = 0; i < N; i++) {