TextToast -- 自定义Toast源码

import android.content.Context;
import android.graphics.Color;
import android.graphics.PixelFormat;
import android.os.Handler;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.WindowManager;
import android.widget.TextView;

/**
 * Created by John on 2016/4/15.
 * 支持设置显示时长,背景,及对齐方式,文字颜色等功能的Toast
 */
public class TextToast {

    /** 默认显示的时间 ms */
    private static final int DURATION = 3000;


    /** top或Bottom对齐时,默认y偏移的值*/
    private static final int DY = (int) dp2px(40);

    private TextView mTextView;
    private final WindowManager mWM;
    private final Handler mHanlder = new Handler();
    private final WindowManager.LayoutParams mParams;
    private int mDuration = DURATION;

    private TextToast(Context context) {

        int dp4 = (int) dp2px(4);
        int dp2 = (int) dp2px(2);

        mTextView = new TextView(context);
        mTextView.setTextColor(Color.argb(0xff, 0x00, 0x00, 0x00));
        mTextView.setBackgroundColor(Color.argb(0x88, 0xff, 0xff, 0xff));
        mTextView.setPadding(dp4, dp2, dp4, dp2);
        mTextView.setGravity(Gravity.CENTER_HORIZONTAL);

        mParams = new WindowManager.LayoutParams();
        mParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
        mParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
        mParams.format = PixelFormat.TRANSLUCENT;
        mParams.type = WindowManager.LayoutParams.TYPE_TOAST;
        mParams.setTitle("Toast");
        mParams.flags = WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON | WindowManager.LayoutParams
                .FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;

        mWM = (WindowManager) context.getApplicationContext().getSystemService(Context.WINDOW_SERVICE);
    }

    /** 创建一个Toast对象*/
    public static TextToast makeText(Context context, CharSequence s) {
        TextToast toast = new TextToast(context);
        toast.setText(s);
        return toast;
    }

    public TextToast setText(CharSequence s) {
        mTextView.setText(s);
        return this;
    }

    public TextToast setBackgroundResource(int resId) {
        mTextView.setBackgroundResource(resId);
        return this;
    }

    public TextToast setBackgroundColor(int color) {
        mTextView.setBackgroundColor(color);
        return this;
    }

    public TextToast setCenter() {
        mParams.gravity = Gravity.CENTER;
        mParams.y = 0;
        return this;
    }

    public TextToast setTop() {
        mParams.gravity = Gravity.TOP;
        mParams.y = DY;
        return this;
    }

    public TextToast setBottom() {
        mParams.gravity = Gravity.BOTTOM;
        mParams.y = DY;
        return this;
    }

    public TextToast setGravity(int gravity, int x, int y) {
        mParams.gravity = gravity;
        mParams.x = x;
        mParams.y = y;
        return this;
    }

    public TextToast setTextColor(int color) {
        mTextView.setTextColor(color);
        return this;
    }

    public TextToast setDuration(int duration) {
        mDuration = duration;
        return this;
    }

    public void show() {
        mHanlder.removeCallbacks(mHide);
        mHanlder.post(mShow);
        mHanlder.postDelayed(mHide, mDuration);
    }

    public void cancel() {
        mHanlder.removeCallbacks(mHide);
        if (mTextView != null && mTextView.getParent() != null)
            mWM.removeViewImmediate(mTextView);
    }

    private static float dp2px(float dp) {
        DisplayMetrics dm = new DisplayMetrics();
        dm.setToDefaults();
        return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, dm);
    }

    private final Runnable mShow = new Runnable() {
        @Override
        public void run() {
            if (mTextView.getParent() != null)
                mWM.removeView(mTextView);
            mWM.addView(mTextView, mParams);
        }
    };

    private Runnable mHide = new Runnable() {
        @Override
        public void run() {
            cancel();
        }
    };
}