android.text.TextPaint#getAlpha ( )源码实例Demo

private void initPaintObjects()
{

    paint = new Paint(Paint.ANTI_ALIAS_FLAG);

    textPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
    textPaint.setTextSize(hintTextSize);
    if (typeface != null)
    {
        textPaint.setTypeface(typeface);
    }
    textPaint.setColor(baseColor);
    baseAlpha = textPaint.getAlpha();

    selectorPath = new Path();
    selectorPath.setFillType(Path.FillType.EVEN_ODD);

    selectorPoints = new Point[3];
    for (int i = 0; i < 3; i++)
    {
        selectorPoints[i] = new Point();
    }
}
 

private void initPaintObjects() {

        int labelTextSize = getResources().getDimensionPixelSize(R.dimen.label_text_size);

        paint = new Paint(Paint.ANTI_ALIAS_FLAG);

        textPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
        textPaint.setTextSize(labelTextSize);
        if (typeface != null) {
            textPaint.setTypeface(typeface);
        }
        textPaint.setColor(baseColor);
        baseAlpha = textPaint.getAlpha();

        selectorPath = new Path();
        selectorPath.setFillType(Path.FillType.EVEN_ODD);

        selectorPoints = new Point[3];
        for (int i = 0; i < 3; i++) {
            selectorPoints[i] = new Point();
        }
    }
 

private void initPaintObjects() {

        int labelTextSize = getResources().getDimensionPixelSize(R.dimen.label_text_size);

        paint = new Paint(Paint.ANTI_ALIAS_FLAG);

        textPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
        textPaint.setTextSize(labelTextSize);
        if (typeface != null) {
            textPaint.setTypeface(typeface);
        }
        textPaint.setColor(baseColor);
        baseAlpha = textPaint.getAlpha();

        selectorPath = new Path();
        selectorPath.setFillType(Path.FillType.EVEN_ODD);

        selectorPoints = new Point[3];
        for (int i = 0; i < 3; i++) {
            selectorPoints[i] = new Point();
        }
    }
 

private void initPaintObjects() {

        int labelTextSize = getResources().getDimensionPixelSize(R.dimen.label_text_size);

        paint = new Paint(Paint.ANTI_ALIAS_FLAG);

        textPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
        textPaint.setTextSize(labelTextSize);
        if (typeface != null) {
            textPaint.setTypeface(typeface);
        }
        textPaint.setColor(baseColor);
        baseAlpha = textPaint.getAlpha();

        selectorPath = new Path();
        selectorPath.setFillType(Path.FillType.EVEN_ODD);

        selectorPoints = new Point[3];
        for (int i = 0; i < 3; i++) {
            selectorPoints[i] = new Point();
        }
    }
 

private TextProgressDrawable(Builder builder) {
  mTextPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
  mTextPaint.setStyle(Paint.Style.FILL);
  mTextPaint.setColor(builder.mTextColor);
  mTextPaint.setTextSize(builder.mTextSize);

  Paint.FontMetrics fm = mTextPaint.getFontMetrics();
  mText = builder.mText;
  mTextHeight = Math.round(fm.descent - fm.ascent);
  mTextWidth = Math.round(mTextPaint.measureText(mText, 0, mText.length()));

  mMaxAlpha = mTextPaint.getAlpha();
  mFBounds = new Rect();

  mAlphaAnimator = ValueAnimator.ofFloat(1f, 0f, 1f);
  mAlphaAnimator.setDuration(builder.mDuration);
  mAlphaAnimator.setRepeatCount(ValueAnimator.INFINITE);
  mAlphaAnimator.addUpdateListener(this);
}
 

/**
 * Progress through the morph:  0 = character, 1 = •
 */
void draw(Canvas canvas, TextPaint paint, CharSequence password,
          int index, float charWidth, float progress) {
    int alpha = paint.getAlpha();
    float x = charWidth * index;

    // draw the character
    canvas.save();
    float textScale = lerp(1f, textToMaskScale, progress);
    // scale character: shrinks to/grows from the mask's height
    canvas.scale(textScale, textScale, x + bounds.exactCenterX(), bounds.exactCenterY());
    // cross fade between the character/mask
    paint.setAlpha((int) lerp(alpha, 0, progress));
    // vertically move the character center toward/from the mask center
    canvas.drawText(password, index, index + 1,
            x, lerp(0f, textOffsetY, progress) / textScale, paint);
    canvas.restore();

    // draw the mask
    canvas.save();
    float maskScale = lerp(maskToTextScale, 1f, progress);
    // scale the mask: down from/up to the character width
    canvas.scale(maskScale, maskScale, x + bounds.exactCenterX(), bounds.exactCenterY());
    // cross fade between the mask/character
    paint.setAlpha((int) AnimUtils.lerp(0, alpha, progress));
    // vertically move the mask center from/toward the character center
    canvas.drawText(PASSWORD_MASK, 0, 1, x, -lerp(textOffsetY, 0f, progress), paint);
    canvas.restore();

    // restore the paint to how we found it
    paint.setAlpha(alpha);
}