android-snippets

CustomTitleView.java

/**
 * Created by searover on 3/29/15.
 */
public class CustomTitleView extends View {

    /**
     * 文本
     */
    private String mTitleText;

    /**
     * 文本颜色
     */
    private int mTitleTextColor;

    /**
     * 文本大小
     */
    private int mTitleTextSize;

    /**
     * 绘制时控制文本绘制的范围
     */
    private Rect mBound;
    private Paint mPaint;

    private static final String TAG = "CustomTitleView";

    public CustomTitleView(Context context) {
        this(context, null);
    }

    public CustomTitleView(Context context, AttributeSet attrs) {
        this(context,attrs,0);
    }

    /**
     * 获取我们自定义的样式属性
     * @param context
     * @param attrs
     * @param defStyleAttr
     */
    public CustomTitleView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context,attrs,defStyleAttr);
        TypedArray array = context.getTheme()
                .obtainStyledAttributes(attrs, R.styleable.CustomTitleView, defStyleAttr, 0);
        int count = array.getIndexCount();
        for (int i = 0; i < count; i++) {
            int attr = array.getIndex(i);
            switch (attr) {
                case R.styleable.CustomTitleView_titleText:
                    mTitleText = array.getString(attr);
                    break;
                case R.styleable.CustomTitleView_titleTextColor:
                    mTitleTextColor = array.getColor(attr, Color.BLACK);
                    break;
                case R.styleable.CustomTitleView_titleTextSize:
                    mTitleTextSize = array.getDimensionPixelSize(attr,
                            (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,
                                    16, getResources().getDisplayMetrics()));
                    break;
            }
        }
        array.recycle();

        // 获得绘制文本的宽和高
        mPaint = new Paint();
        mPaint.setTextSize(mTitleTextSize);
        mBound = new Rect();
        mPaint.getTextBounds(mTitleText, 0, mTitleText.length(), mBound);
        this.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                mTitleText = randomText();
//                postInvalidate();
//                invalidate();
                new Thread(){
                    public void run(){
                        postInvalidate();
                    }
                }.start();
            }

            private String randomText() {
                Random random = new Random();
                Set<Integer> set = new HashSet<Integer>();
                while (set.size() < 4){
                    int randomInt = random.nextInt(10);
                    set.add(randomInt);
                }
                StringBuilder builder = new StringBuilder();
                for (Integer i : set){
                    builder.append("" + i);
                }
                return builder.toString();
            }
        });
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){

        Log.d(TAG,"onMeasure method called");
        int width = 0;
        int height = 0;

        int specMode = MeasureSpec.getMode(widthMeasureSpec);
        int specSize = MeasureSpec.getSize(widthMeasureSpec);

        switch (specMode){
            case MeasureSpec.EXACTLY:
                width = getPaddingLeft() + getPaddingRight() + specSize;
                break;
            case MeasureSpec.AT_MOST:
                width = getPaddingLeft() + getPaddingRight() + mBound.width();
                break;
        }
        specMode =  MeasureSpec.getMode(heightMeasureSpec);
        specSize = MeasureSpec.getSize(heightMeasureSpec);
        switch (specMode){
            case MeasureSpec.EXACTLY:
                height = getPaddingTop() + getPaddingBottom() + specSize;
                break;
            case MeasureSpec.AT_MOST:
                height = getPaddingTop() + getPaddingBottom() + mBound.height();
                break;
        }
        setMeasuredDimension(width,height);
    }

    @Override
    protected void onDraw(Canvas canvas){
        Log.w(TAG,"onDraw method has been called");
        mPaint.setColor(Color.YELLOW);
        canvas.drawRect(0,0,getMeasuredWidth(),getMeasuredHeight(),mPaint);

        mPaint.setColor(mTitleTextColor);
        canvas.drawText(mTitleText,getWidth() / 2 - mBound.width() / 2,
                getHeight() / 2 + mBound.height() / 2, mPaint);
    }
}