src/com/android/deskclock/DeskClockFragment.java

/*
 * Copyright (C) 2012 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.deskclock;

import android.view.KeyEvent;
import android.widget.ImageView;

import androidx.annotation.Keep;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;

import com.android.deskclock.uidata.UiDataModel;
import com.android.deskclock.uidata.UiDataModel.Tab;

public abstract class DeskClockFragment extends Fragment implements FabContainer, FabController {

    /** The tab associated with this fragment. */
    private final Tab mTab;

    /** The container that houses the fab and its left and right buttons. */
    private FabContainer mFabContainer;

    public DeskClockFragment(Tab tab) {
        mTab = tab;
    }

    @Override
    public void onResume() {
        super.onResume();

        // Update the fab and buttons in case their state changed while the fragment was paused.
        if (isTabSelected()) {
            updateFab(FAB_AND_BUTTONS_IMMEDIATE);
        }
    }

    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // By default return false so event continues to propagate
        return false;
    }

    @Override
    public void onLeftButtonClick(@NonNull ImageView left) {
        // Do nothing here, only in derived classes
    }

    @Override
    public void onRightButtonClick(@NonNull ImageView right) {
        // Do nothing here, only in derived classes
    }

    @Override
    public void onMorphFab(@NonNull ImageView fab) {
        // Do nothing here, only in derived classes
    }

    /**
     * @param fabContainer the container that houses the fab and its left and right buttons
     */
    public final void setFabContainer(FabContainer fabContainer) {
        mFabContainer = fabContainer;
    }

    /**
     * Requests that the parent activity update the fab and buttons.
     *
     * @param updateTypes the manner in which the fab container should be updated
     */
    @Override
    public final void updateFab(@UpdateFabFlag int updateTypes) {
        if (mFabContainer != null) {
            mFabContainer.updateFab(updateTypes);
        }
    }

    /**
     * @return {@code true} iff the currently selected tab displays this fragment
     */
    public final boolean isTabSelected() {
        return UiDataModel.getUiDataModel().getSelectedTab() == mTab;
    }

    /**
     * Select the tab that displays this fragment.
     */
    @Keep
    public final void selectTab() {
        UiDataModel.getUiDataModel().setSelectedTab(mTab);
    }

    /**
     * Updates the scrolling state in the {@link UiDataModel} for this tab.
     *
     * @param scrolledToTop {@code true} iff the vertical scroll position of this tab is at the top
     */
    public final void setTabScrolledToTop(boolean scrolledToTop) {
        UiDataModel.getUiDataModel().setTabScrolledToTop(mTab, scrolledToTop);
    }
}