com/android/settingslib/collapsingtoolbar/CollapsingToolbarBaseActivity.java

/*
 * Copyright (C) 2021 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.settingslib.collapsingtoolbar;

import android.app.ActionBar;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toolbar;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.coordinatorlayout.widget.CoordinatorLayout;
import androidx.fragment.app.FragmentActivity;

import com.android.settingslib.utils.BuildCompatUtils;

import com.google.android.material.appbar.AppBarLayout;
import com.google.android.material.appbar.CollapsingToolbarLayout;
import com.google.android.material.resources.TextAppearanceConfig;

/**
 * A base Activity that has a collapsing toolbar layout is used for the activities intending to
 * enable the collapsing toolbar function.
 */
public class CollapsingToolbarBaseActivity extends FragmentActivity {

    private static final float TOOLBAR_LINE_SPACING_MULTIPLIER = 1.1f;

    @Nullable
    private CollapsingToolbarLayout mCollapsingToolbarLayout;
    @Nullable
    private AppBarLayout mAppBarLayout;
    private int mCustomizeLayoutResId = 0;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (mCustomizeLayoutResId > 0 && !BuildCompatUtils.isAtLeastS()) {
            super.setContentView(mCustomizeLayoutResId);
            return;
        }
        // Force loading font synchronously for collapsing toolbar layout
        TextAppearanceConfig.setShouldLoadFontSynchronously(true);
        super.setContentView(R.layout.collapsing_toolbar_base_layout);
        mCollapsingToolbarLayout = findViewById(R.id.collapsing_toolbar);
        mAppBarLayout = findViewById(R.id.app_bar);
        if (mCollapsingToolbarLayout != null) {
            mCollapsingToolbarLayout.setLineSpacingMultiplier(TOOLBAR_LINE_SPACING_MULTIPLIER);
        }
        disableCollapsingToolbarLayoutScrollingBehavior();

        final Toolbar toolbar = findViewById(R.id.action_bar);
        setActionBar(toolbar);

        // Enable title and home button by default
        final ActionBar actionBar = getActionBar();
        if (actionBar != null) {
            actionBar.setDisplayHomeAsUpEnabled(true);
            actionBar.setHomeButtonEnabled(true);
            actionBar.setDisplayShowTitleEnabled(true);
        }
    }

    @Override
    public void setContentView(int layoutResID) {
        final ViewGroup parent = findViewById(R.id.content_frame);
        if (parent != null) {
            parent.removeAllViews();
        }
        LayoutInflater.from(this).inflate(layoutResID, parent);
    }

    @Override
    public void setContentView(View view) {
        final ViewGroup parent = findViewById(R.id.content_frame);
        if (parent != null) {
            parent.addView(view);
        }
    }

    @Override
    public void setContentView(View view, ViewGroup.LayoutParams params) {
        final ViewGroup parent = findViewById(R.id.content_frame);
        if (parent != null) {
            parent.addView(view, params);
        }
    }

    /**
     * This method allows an activity to replace the default layout with a customize layout. Notice
     * that it will no longer apply the features being provided by this class when this method
     * gets called.
     */
    protected void setCustomizeContentView(int layoutResId) {
        mCustomizeLayoutResId = layoutResId;
    }

    @Override
    public void setTitle(CharSequence title) {
        if (mCollapsingToolbarLayout != null) {
            mCollapsingToolbarLayout.setTitle(title);
        } else {
            super.setTitle(title);
        }
    }

    @Override
    public void setTitle(int titleId) {
        if (mCollapsingToolbarLayout != null) {
            mCollapsingToolbarLayout.setTitle(getText(titleId));
        } else {
            super.setTitle(titleId);
        }
    }

    @Override
    public boolean onNavigateUp() {
        if (!super.onNavigateUp()) {
            finishAfterTransition();
        }
        return true;
    }

    /**
     * Returns an instance of collapsing toolbar.
     */
    @Nullable
    public CollapsingToolbarLayout getCollapsingToolbarLayout() {
        return mCollapsingToolbarLayout;
    }

    /**
     * Return an instance of app bar.
     */
    @Nullable
    public AppBarLayout getAppBarLayout() {
        return mAppBarLayout;
    }

    private void disableCollapsingToolbarLayoutScrollingBehavior() {
        if (mAppBarLayout == null) {
            return;
        }
        final CoordinatorLayout.LayoutParams params =
                (CoordinatorLayout.LayoutParams) mAppBarLayout.getLayoutParams();
        final AppBarLayout.Behavior behavior = new AppBarLayout.Behavior();
        behavior.setDragCallback(
                new AppBarLayout.Behavior.DragCallback() {
                    @Override
                    public boolean canDrag(@NonNull AppBarLayout appBarLayout) {
                        return false;
                    }
                });
        params.setBehavior(behavior);
    }
}