Android 带箭头的指引TipLayout实现。

image1.png image2.png

如上设计图，要求三角形指示器需要动态对齐上面的文本，需要动态的实现对其三角形。

引用方式

compile 'com.xiaowei:TriangleTipLayout:1.0.0'
//or
implementation ‘com.xiaowei:TriangleTipLayout:1.0.0’

实现思路

准备一个三角形指引的图片即可。
先上代码

final TextPaint textPaint = mTextView.getPaint();
        final int textHeight = (int) (textPaint.descent() - textPaint.ascent());
        mRect.set(0, DEFAULT_TOP_HEIGHT, getWidth(), getHeight() + textHeight - DEFAULT_TOP_HEIGHT);
        canvas.drawRect(mRect, mRectPaint);
        final String text = mTextView.getText().toString();
        float left = 0;
        if (mIsShowTriangle) {
            if (mGravity == Gravity.LEFT || mGravity == Gravity.START) {
                LayoutParams layoutParams = (LayoutParams) mTarget.getLayoutParams();
                left = mTarget.getLeft() - layoutParams.rightMargin - layoutParams.leftMargin;
            } else {
                if (mTarget instanceof TextView) {
                    ViewParent viewParent = mTarget.getParent();
                    float textWidth = textPaint.measureText(text);
                    if (viewParent instanceof LinearLayout) {
                        final float width = mTarget.getWidth() / 2;
                        left = mTarget.getLeft() + width - (mBitmap.getWidth() / 2);
                    } else if (viewParent instanceof RelativeLayout) {
                        left = mTarget.getLeft() + textWidth / 2;
                    }
                } else if (mTarget instanceof ImageView) {
                    final float width = mTarget.getWidth();
                    left = mTarget.getLeft() + (width / 2) - (mBitmap.getWidth() / 2);
                }
            }
            canvas.drawBitmap(mBitmap, left, 0, mBitmapPaint);
        }
    }

核心代码如上,其思路是先绘制一个矩形，预留出三角形指示器图片所需要的高度，最后将其三行图片绘制出来。

配置指示器

        mTipsLayout.setRectBackgroundColor(Color.parseColor("#FFF8BE"));
        mTipsLayout.setTextColor(Color.parseColor("#FF9B33"));
        mTipsLayout.setTriangleBitmap(BitmapFactory.decodeResource(getResources(), R.mipmap.ic_triangle_arrow));
        mTipsLayout.setTriangleGravity(Gravity.START);
        mTipsLayout.bindView(findViewById(R.id.text2));
        mTipsLayout.setText("您今日收入已到达10W+，牛逼。保持努力");

注意：当调用setText之后会invalidate()重新绘制;

实现效果如下:

image1.gif

Feature

todo

About

GitHub:Github/xwdz/TriangleTipLayout