java - 带有旋转图标的旋转轮

Question

现在，这些天我正在研究旋转轮，可能附有屏幕截图。

我从 github https://github.com/R4md4c/AndroidRotaryWheelView 找到了代码困难在于我无法在滚轮旋转期间将图标保持在垂直位置。图标以其轮子段的形式旋转，同时要求它们在最初显示时保持垂直位置(如屏幕截图 1 所示)。

我必须自定义以下代码，我需要更改特定可绘制矩形的边界。

我发现自己无法实现引用文献中的精确计算。

任何帮助将不胜感激。

    @Override
public void onDraw(Canvas canvas) {
// set the height of Wheel childs items
    canvas.scale(getWidth() / mViewRect.width(), getHeight() / 2
            / mViewRect.width(), xPosition, yPosition);


    canvas.save(Canvas.MATRIX_SAVE_FLAG); // Saving the canvas and later
                                            // restoring it so only this
                                            // image will be rotated.
    canvas.rotate((float) mRotationAngle, xPosition, yPosition);

    for (int i = 0; i < mWedges.length; i++) {
        Wedge f = mWedges[i];
        mPaint.setColor(SEGMENT_COLOR);
        mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
        canvas.drawPath(f, mPaint);

        Rect rf = iconRect[i];

        if ((mMenuEntries.get(i).getIcon() != 0)
                && (mMenuEntries.get(i).getLabel() != null)) {

            System.out.println("the canvasd drawn ........");

            // This will look for a "new line" and split into multiple lines
            String menuItemName = mMenuEntries.get(i).getLabel();
            String[] stringArray = menuItemName.split("\n");

            mPaint.setColor(textColor);

            mPaint.setStyle(Paint.Style.FILL);
            // mPaint.setTextSize(textSize);

            Rect rect = new Rect();
            float textHeight = 0;
            for (int j = 0; j < stringArray.length; j++) {
                mPaint.getTextBounds(stringArray[j], 0,
                        stringArray[j].length(), rect);
                textHeight = textHeight + (rect.height() + 3);
            }

            Rect rf2 = new Rect();
            rf2.set(rf.left, rf.top - ((int) textHeight / 2), rf.right,
                    rf.bottom - ((int) textHeight / 2));

            float textBottom = rf2.bottom;
            for (int j = 0; j < stringArray.length; j++) {
                mPaint.getTextBounds(stringArray[j], 0,
                        stringArray[j].length(), rect);
                float textLeft = rf.centerX() - rect.width() / 2;
                textBottom = textBottom + (rect.height() + 3);
                mPaint.setTextSize(scalePX(8));
                canvas.drawText(stringArray[j], textLeft - rect.left,
                        textBottom - rect.bottom, mPaint);
            }

            // canvas.rotate((float)mRotationAngle,
            // rf.top-((int)textHeight/2), rf.bottom-((int)textHeight/2));
            int index = checkSelection(canvas);
            rf2 = rotaionRf(rf2, mRotationAngle);


            if (i == index) {
                // Puts in the Icon
                Drawable drawable = getResources().getDrawable(
                        mMenuEntries.get(i).getIconSelected());
                drawable.setBounds(rf2);
                drawable.draw(canvas);

            } else {
                // Puts in the Icon
                Drawable drawable = getResources().getDrawable(
                        mMenuEntries.get(i).getIcon());
                drawable.setBounds(rf2);
                drawable.draw(canvas);
            }
            // Icon Only
        } else if (mMenuEntries.get(i).getIcon() != 0) {

            System.out.println("the canvasd drawn ELSE........");

            // Puts in the Icon
            Drawable drawable = getResources().getDrawable(
                    mMenuEntries.get(i).getIconSelected());
            drawable.setBounds(rf);

            drawable.draw(canvas);

            // Text Only
        } else {
            // Puts in the Text if no Icon
            mPaint.setColor(this.textColor);

            /*
             * if (f != enabled && Wedge2Shown == true) {
             * mPaint.setAlpha(disabledAlpha); } else {
             * mPaint.setAlpha(textAlpha); }
             */
            // mPaint.setAlpha(textAlpha);
            mPaint.setStyle(Paint.Style.FILL);
            // mPaint.setTextSize(textSize);

            // This will look for a "new line" and split into multiple lines
            String menuItemName = mMenuEntries.get(i).getLabel();
            String[] stringArray = menuItemName.split("\n");

            // gets total height
            Rect rect = new Rect();
            float textHeight = 0;
            for (int j = 0; j < stringArray.length; j++) {
                mPaint.getTextBounds(stringArray[j], 0,
                        stringArray[j].length(), rect);
                textHeight = textHeight + (rect.height() + 3);
            }

            float textBottom = rf.centerY() - (textHeight / 2);
            for (int j = 0; j < stringArray.length; j++) {
                mPaint.getTextBounds(stringArray[j], 0,
                        stringArray[j].length(), rect);
                float textLeft = rf.centerX() - rect.width() / 2;
                textBottom = textBottom + (rect.height() + 3);
                canvas.drawText(stringArray[j], textLeft - rect.left,
                        textBottom - rect.bottom, mPaint);

            }

            // canvas.drawTextOnPath(text, path, hOffset, vOffset, paint)
            // canvas.rotate((float)mRotationAngle, xPosition, yPosition );
            // canvas.drawRect(rf, mPaint);

        }
        // canvas.restore();
    }
    // canvas.restore();
    canvas.restore();

    // System.out.println()
    canvas.save();

    canvas.restore();


    mPaint.setShader(mShader);
    // mPaint.setAlpha(0x66);
    // Draw the Selection Segment
    if (mSelectionWedge != null) {
        canvas.drawPath(mSelectionWedge, mPaint);
        // canvas.drawRect(mSelectionWedge.getWedgeRegion().getBounds(),
        // mPaint);
    }

    mPaint.setShader(null);



    int index = checkSelection(canvas);

    System.out.println("the index=====" + index);

    if (checkSelection(canvas) != -1) {
    }
}

Answer 1

在使用canvas.rotate时，你必须确保你给它的x&y值是主轮中心。