src/com/android/wallpaper/widget/DuoTabs.java

/*
 * Copyright (C) 2022 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.wallpaper.widget;

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.widget.Button;
import android.widget.FrameLayout;

import androidx.annotation.IntDef;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import com.android.wallpaper.R;
import com.android.wallpaper.util.SystemColors;

/**
 * Custom layout for duo tabs.
 */
public final class DuoTabs extends FrameLayout {

    public static final int TAB_PRIMARY = 0;
    public static final int TAB_SECONDARY = 1;

    /**
     * Overlay tab
     */
    @IntDef({TAB_PRIMARY, TAB_SECONDARY})
    public @interface Tab {
    }

    /**
     * Overlay tab selected listener
     */
    public interface OnTabSelectedListener {

        /**
         * On tab selected
         */
        void onTabSelected(@Tab int tab);
    }

    OnTabSelectedListener mOnTabSelectedListener;
    Button mPrimaryTab;
    Button mSecondaryTab;
    @Tab int mCurrentOverlayTab;

    /**
     * Constructor
     */
    public DuoTabs(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        LayoutInflater.from(context).inflate(R.layout.duo_tabs, this, true);
        mPrimaryTab = findViewById(R.id.tab_primary);
        mSecondaryTab = findViewById(R.id.tab_secondary);
        mPrimaryTab.setOnClickListener(v -> selectTab(TAB_PRIMARY));
        mSecondaryTab.setOnClickListener(v -> selectTab(TAB_SECONDARY));
    }

    /**
     * Set tab text
     */
    public void setTabText(String primaryTabText, String secondaryTabText) {
        mPrimaryTab.setText(primaryTabText);
        mSecondaryTab.setText(secondaryTabText);
    }

    /**
     * Select a tab
     */
    public void selectTab(@Tab int tab) {
        updateTabIndicator(tab);
        if (mOnTabSelectedListener != null) {
            mOnTabSelectedListener.onTabSelected(tab);
        }
        mCurrentOverlayTab = tab;
    }

    /**
     * Set listener
     */
    public void setOnTabSelectedListener(
            OnTabSelectedListener onTabSelectedListener) {
        mOnTabSelectedListener = onTabSelectedListener;
    }

    /**
     * Update the background color in case the context theme has changed.
     */
    public void updateBackgroundColor() {
        mPrimaryTab.setBackground(null);
        mSecondaryTab.setBackground(null);
        updateTabIndicator(mCurrentOverlayTab);
    }

    private void updateTabIndicator(@Tab int tab) {
        Context c = getContext();
        mPrimaryTab.setBackgroundResource(
                tab == TAB_PRIMARY
                        ? R.drawable.duo_tabs_button_indicator_background
                        : R.drawable.duo_tabs_button_background);
        mPrimaryTab.setTextColor(
                tab == TAB_PRIMARY
                        ? getResources().getColor(R.color.text_color_on_accent)
                        : SystemColors.getColor(c, android.R.attr.textColorPrimary));
        mSecondaryTab.setBackgroundResource(
                tab == TAB_SECONDARY
                        ? R.drawable.duo_tabs_button_indicator_background
                        : R.drawable.duo_tabs_button_background);
        mSecondaryTab.setTextColor(
                tab == TAB_SECONDARY
                        ? getResources().getColor(R.color.text_color_on_accent)
                        : SystemColors.getColor(c, android.R.attr.textColorPrimary));
    }

    public @Tab int getSelectedTab() {
        return mCurrentOverlayTab;
    }
}