/**
* Finish a mouse drag operation. Nothing is done unless the current tool is a shape tool. For
* shape tools, the user's shape is drawn to the off-screen canvas, making it a permanent part
* of the picture, and then the repaint() method is called to show the modified picture on the
* screen.
*/
@Override
public void mouseReleased(MouseEvent evt) {
dragging = false;
if (SHAPE_TOOLS.contains(currentTool)) {
Graphics g = OSC.getGraphics();
g.setColor(currentColor);
putCurrentShape(g);
g.dispose();
repaint();
}
}
/**
* Continue a drag operation when the user drags the mouse. For the CURVE tool, a line is drawn
* from the previous mouse position to the current mouse position in the off-screen canvas, and
* the repaint() method is called for a rectangle that contains the line segment that was drawn.
* For shape tools, the off-screen canvas is not changed, but the repaint() method is called so
* that the paintComponent() method can redraw the picture with the user's shape in the new
* position. For the SMUDGE and ERASE tools, the tool is applied along a line from the previous
* mouse position to the current position;
*/
@Override
public void mouseDragged(MouseEvent evt) {
currentX = evt.getX();
currentY = evt.getY();
if (currentTool == Tool.CURVE) {
Graphics g = OSC.getGraphics();
g.setColor(currentColor);
g.drawLine(prevX, prevY, currentX, currentY);
g.dispose();
repaintRect(prevX, prevY, currentX, currentY);
} else if (SHAPE_TOOLS.contains(currentTool)) {
// Repaint the rectangles occupied by the previous position of
// the shape and by its current position.
repaintRect(startX, startY, prevX, prevY);
repaintRect(startX, startY, currentX, currentY);
} else {
// Tool has to be ERASE or SMUDGE
applyToolAlongLine(prevX, prevY, currentX, currentY);
}
prevX = currentX;
prevY = currentY;
}