SizeUtils.java

package lzf.video.edit.utils;

import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.View;
import android.view.ViewGroup;

/**
 * <pre>
 *     author: Blankj
 *     blog  : http://blankj.com
 *     time  : 2016/8/2
 *     desc  : 尺寸相关工具类
 * </pre>
 */
public class SizeUtils {

    private SizeUtils() {
        throw new UnsupportedOperationException("u can't instantiate me...");
    }

    /**
     * dp转px
     *
     * @param dpValue dp值
     * @return px值
     */
    public static int dp2px(float dpValue) {
        final float scale = Utils.getContext().getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }

    /**
     * px转dp
     *
     * @param pxValue px值
     * @return dp值
     */
    public static int px2dp( float pxValue) {
        final float scale = Utils.getContext().getResources().getDisplayMetrics().density;
        return (int) (pxValue / scale + 0.5f);
    }

    /**
     * sp转px
     *
     * @param spValue sp值
     * @return px值
     */
    public static int sp2px(float spValue) {
        final float fontScale = Utils.getContext().getResources().getDisplayMetrics().scaledDensity;
        return (int) (spValue * fontScale + 0.5f);
    }

    /**
     * px转sp
     *
     * @param pxValue px值
     * @return sp值
     */
    public static int px2sp( float pxValue) {
        final float fontScale = Utils.getContext().getResources().getDisplayMetrics().scaledDensity;
        return (int) (pxValue / fontScale + 0.5f);
    }

    /**
     * 各种单位转换
     * <p>该方法存在于TypedValue</p>
     *
     * @param unit    单位
     * @param value   值
     * @param metrics DisplayMetrics
     * @return 转换结果
     */
    public static float applyDimension(int unit, float value, DisplayMetrics metrics) {
        switch (unit) {
            case TypedValue.COMPLEX_UNIT_PX:
                return value;
            case TypedValue.COMPLEX_UNIT_DIP:
                return value * metrics.density;
            case TypedValue.COMPLEX_UNIT_SP:
                return value * metrics.scaledDensity;
            case TypedValue.COMPLEX_UNIT_PT:
                return value * metrics.xdpi * (1.0f / 72);
            case TypedValue.COMPLEX_UNIT_IN:
                return value * metrics.xdpi;
            case TypedValue.COMPLEX_UNIT_MM:
                return value * metrics.xdpi * (1.0f / 25.4f);
        }
        return 0;
    }

    /**
     * 在onCreate中获取视图的尺寸
     * <p>需回调onGetSizeListener接口，在onGetSize中获取view宽高</p>
     * <p>用法示例如下所示</p>
     * <pre>
     * SizeUtils.forceGetViewSize(view, new SizeUtils.onGetSizeListener() {
     *     Override
     *     public void onGetSize(View view) {
     *         view.getWidth();
     *     }
     * });
     * </pre>
     *
     * @param view     视图
     * @param listener 监听器
     */
    public static void forceGetViewSize(final View view, final onGetSizeListener listener) {
        view.post(new Runnable() {
            @Override
            public void run() {
                if (listener != null) {
                    listener.onGetSize(view);
                }
            }
        });
    }

    /**
     * 获取到View尺寸的监听
     */
    public interface onGetSizeListener {
        void onGetSize(View view);
    }

    public static void setListener(onGetSizeListener listener) {
        mListener = listener;
    }

    private static onGetSizeListener mListener;

    /**
     * 测量视图尺寸
     *
     * @param view 视图
     * @return arr[0]: 视图宽度, arr[1]: 视图高度
     */
    public static int[] measureView(View view) {
        ViewGroup.LayoutParams lp = view.getLayoutParams();
        if (lp == null) {
            lp = new ViewGroup.LayoutParams(
                    ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT
            );
        }
        int widthSpec = ViewGroup.getChildMeasureSpec(0, 0, lp.width);
        int lpHeight = lp.height;
        int heightSpec;
        if (lpHeight > 0) {
            heightSpec = View.MeasureSpec.makeMeasureSpec(lpHeight, View.MeasureSpec.EXACTLY);
        } else {
            heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        }
        view.measure(widthSpec, heightSpec);
        return new int[]{view.getMeasuredWidth(), view.getMeasuredHeight()};
    }

    /**
     * 获取测量视图宽度
     *
     * @param view 视图
     * @return 视图宽度
     */
    public static int getMeasuredWidth(View view) {
        return measureView(view)[0];
    }

    /**
     * 获取测量视图高度
     *
     * @param view 视图
     * @return 视图高度
     */
    public static int getMeasuredHeight(View view) {
        return measureView(view)[1];
    }
}