CollapsingTextHelper.java 文件源码

private void ensureExpandedTexture() {
    if (this.mExpandedTitleTexture == null && !this.mExpandedBounds.isEmpty() && !TextUtils.isEmpty(this.mTextToDraw)) {
        calculateOffsets(0.0f);
        this.mTextureAscent = this.mTextPaint.ascent();
        this.mTextureDescent = this.mTextPaint.descent();
        int w = Math.round(this.mTextPaint.measureText(this.mTextToDraw, 0, this.mTextToDraw.length()));
        int h = Math.round(this.mTextureDescent - this.mTextureAscent);
        if (w > 0 && h > 0) {
            this.mExpandedTitleTexture = Bitmap.createBitmap(w, h, Config.ARGB_8888);
            new Canvas(this.mExpandedTitleTexture).drawText(this.mTextToDraw, 0, this.mTextToDraw.length(), 0.0f, ((float) h) - this.mTextPaint.descent(), this.mTextPaint);
            if (this.mTexturePaint == null) {
                this.mTexturePaint = new Paint(3);
            }
        }
    }
}