src/com/android/launcher3/util/HorizontalInsettableView.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.launcher3.util;

import android.util.FloatProperty;

/**
 * Allows the implementing view to add insets to the left and right.
 */
public interface HorizontalInsettableView {

    /**
     * Sets left and right insets for the view so it looks like the width of the view is
     * reduced when inset is increased.
     *
     * The inset is calculated based on the width of the view: e.g. when the width of
     * the view is 100px then if we apply 0.15f horizontal inset percentage the rendered width
     * of the view will be 70px with 15px of padding on the left and right sides.
     *
     * @param insetPercentage width percentage to inset the content from the left and from the right
     */
    void setHorizontalInsets(float insetPercentage);

    /**
     * Returns the width percentage to inset the content from the left and from the right. See
     * {@link #setHorizontalInsets};
     */
    float getHorizontalInsets();

    FloatProperty<HorizontalInsettableView> HORIZONTAL_INSETS =
            new FloatProperty<HorizontalInsettableView>("horizontalInsets") {
                @Override
                public Float get(HorizontalInsettableView view) {
                    return view.getHorizontalInsets();
                }

                @Override
                public void setValue(HorizontalInsettableView view, float insetPercentage) {
                    view.setHorizontalInsets(insetPercentage);
                }
            };
}