Increases the hit rect of a view. - Android User Interface

Description

Increases the hit rect of a view.
Demo Code

/*/*  w  w w .j  a va2s . c om*/
 * Copyright 2012 Kevin Sawicki <kevinsawicki@gmail.com>
 *
 * 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.book2s;
import android.graphics.Rect;
import android.util.DisplayMetrics;
import android.view.TouchDelegate;
import android.view.View;

public class Main {
    /**
     * Increases the hit rect of a view. This should be used when an icon is small and cannot be easily tapped on.
     * Source: http://stackoverflow.com/a/1343796/5210
     *
     * @param amount   The amount of dp's to be added to all four sides of the view hit purposes.
     * @param delegate The view that needs to have its hit rect increased.
     */
    public static void increaseHitRectBy(final int amount,
            final View delegate) {
        increaseHitRectBy(amount, amount, amount, amount, delegate);
    }

    /**
     * Increases the hit rect of a view. This should be used when an icon is small and cannot be easily tapped on.
     * Source: http://stackoverflow.com/a/1343796/5210
     *
     * @param top      The amount of dp's to be added to the top for hit purposes.
     * @param left     The amount of dp's to be added to the left for hit purposes.
     * @param bottom   The amount of dp's to be added to the bottom for hit purposes.
     * @param right    The amount of dp's to be added to the right for hit purposes.
     * @param delegate The view that needs to have its hit rect increased.
     */
    public static void increaseHitRectBy(final int top, final int left,
            final int bottom, final int right, final View delegate) {
        final View parent = (View) delegate.getParent();
        if (parent != null && delegate.getContext() != null) {
            parent.post(new Runnable() {
                // Post in the parent's message queue to make sure the parent
                // lays out its children before we call getHitRect()
                public void run() {
                    final float densityDpi = delegate.getContext()
                            .getResources().getDisplayMetrics().densityDpi;
                    final Rect r = new Rect();
                    delegate.getHitRect(r);
                    r.top -= transformToDensityPixel(top, densityDpi);
                    r.left -= transformToDensityPixel(left, densityDpi);
                    r.bottom += transformToDensityPixel(bottom, densityDpi);
                    r.right += transformToDensityPixel(right, densityDpi);
                    parent.setTouchDelegate(new TouchDelegate(r, delegate));
                }
            });
        }
    }

    public static int transformToDensityPixel(int regularPixel,
            DisplayMetrics displayMetrics) {
        return transformToDensityPixel(regularPixel,
                displayMetrics.densityDpi);
    }

    public static int transformToDensityPixel(int regularPixel,
            float densityDpi) {
        return (int) (regularPixel * densityDpi);
    }
}
Increases the hit rect of a view. - Android User Interface

Description

Demo Code

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