TextSelection_custom.java

void drawCustomMethod(Canvas canvas) {
    int startLine = getTouchedLine(startX, startY);
    int startCharPos = getCharPositionByTouch(startX, startY, startLine);

    int currentLine = getTouchedLine(currentX, currentY);
    int currentCharPos = getCharPositionByTouch(currentX, currentY, currentLine);

    if(startLine == currentLine) {
        drawSelection(canvas,startCharPos,currentCharPos,startLine);
        return;
    }

    for (int i = startLine; i <= currentLine; i++) {
        if(startLine == i) {
            drawSelection(canvas,startCharPos,getLayout().getLineEnd(i),i);
            continue;
        }
        if(currentLine == i) {
            drawSelection(canvas,getLayout().getLineStart(i),currentCharPos,i);
            continue;
        }
        drawFullSelection(canvas,i);
    }
}