com/android/systemui/statusbar/phone/ContextualButton.java

/*
 * Copyright (C) 2018 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.systemui.statusbar.phone;

import android.annotation.DrawableRes;
import android.annotation.IdRes;
import android.annotation.NonNull;
import android.content.Context;
import android.view.View;

import com.android.systemui.statusbar.policy.KeyButtonDrawable;
import com.android.systemui.statusbar.policy.KeyButtonView;

/**
 * Simple contextual button that is added to the {@link ContextualButtonGroup}. Extend if need extra
 * functionality.
 */
public class ContextualButton extends ButtonDispatcher {

    private ContextButtonListener mListener;
    private ContextualButtonGroup mGroup;

    protected final @DrawableRes int mIconResId;

    /**
      * Create a contextual button that will use a {@link KeyButtonView} and
      * {@link KeyButtonDrawable} get and show the button from xml to its icon drawable.
      * @param buttonResId the button view from xml layout
      * @param iconResId icon resource to be used
      */
    public ContextualButton(@IdRes int buttonResId, @DrawableRes int iconResId) {
        super(buttonResId);
        mIconResId = iconResId;
    }

    /**
     * Reload the drawable from resource id, should reapply the previous dark intensity.
     */
    public void updateIcon() {
        if (getCurrentView() == null || !getCurrentView().isAttachedToWindow() || mIconResId == 0) {
            return;
        }
        final KeyButtonDrawable currentDrawable = getImageDrawable();
        KeyButtonDrawable drawable = getNewDrawable();
        if (currentDrawable != null) {
            drawable.setDarkIntensity(currentDrawable.getDarkIntensity());
        }
        setImageDrawable(drawable);
    }

    @Override
    public void setVisibility(int visibility) {
        super.setVisibility(visibility);

        // Stop any active animations if hidden
        final KeyButtonDrawable currentDrawable = getImageDrawable();
        if (visibility != View.VISIBLE && currentDrawable != null && currentDrawable.canAnimate()) {
            currentDrawable.clearAnimationCallbacks();
            currentDrawable.resetAnimation();
        }

        if (mListener != null) {
            mListener.onVisibilityChanged(this, visibility == View.VISIBLE);
        }
    }

    public void setListener(ContextButtonListener listener) {
        mListener = listener;
    }

    /**
     * Show this button based on its priority compared to other buttons in the group. If not
     * attached to a group it will set its own visibility to be visible.
     * @return if visible
     */
    public boolean show() {
        if (mGroup == null) {
            setVisibility(View.VISIBLE);
            return true;
        }
        return mGroup.setButtonVisibility(getId(), true /* visible */) == View.VISIBLE;
    }

    /**
     * Hide this button.
     * @return if visible
     */
    public boolean hide() {
        if (mGroup == null) {
            setVisibility(View.INVISIBLE);
            return false;
        }
        return mGroup.setButtonVisibility(getId(), false /* visible */) != View.VISIBLE;
    }

    /**
     * Called when this button was added to the group. Keep a reference to the group to show based
     * on priority compared to other buttons.
     * @param group the holder of all the buttons
     */
    void attachToGroup(@NonNull ContextualButtonGroup group) {
        mGroup = group;
    }

    protected KeyButtonDrawable getNewDrawable() {
        return KeyButtonDrawable.create(getContext().getApplicationContext(), mIconResId,
                false /* shadow */);
    }

    /**
     * This context is from the view that could be stale after rotation or config change. To get
     * correct resources use getApplicationContext() as well.
     * @return current view context
     */
    protected Context getContext() {
        return getCurrentView().getContext();
    }

    public interface ContextButtonListener {
        void onVisibilityChanged(ContextualButton button, boolean visible);
    }
}