/**
* When the ERASE or SMUDGE tools are used and the mouse jumps from (x1,y1) to (x2,y2), the tool
* has to be applied to a line of pixel positions between the two points in order to cover the
* entire line that the mouse moves along. The change is made to the off-screen canvas, and
* repaint() is called to copy the changes to the screen.
*/
void applyToolAlongLine(int x1, int y1, int x2, int y2) {
Graphics g = OSC.getGraphics();
g.setColor(fillColor); // (for ERASE only)
int w = OSC.getWidth(); // (for SMUDGE only)
int h = OSC.getHeight(); // (for SMUDGE only)
int dist = Math.max(Math.abs(x2 - x1), Math.abs(y2 - y1));
// dist is the number of points along the line from
// (x1,y1) to (x2,y2) at which the tool will be applied.
double dx = (double) (x2 - x1) / dist;
double dy = (double) (y2 - y1) / dist;
for (int d = 1; d <= dist; d++) {
// Apply the tool at one of the points (x,y) along the
// line from (x1,y1) to (x2,y2).
int x = (int) Math.round(x1 + dx * d);
int y = (int) Math.round(y1 + dy * d);
if (currentTool == Tool.ERASE) {
// Erase a 10-by-10 block of pixels around (x,y)
g.fillRect(x - 5, y - 5, 10, 10);
repaint(x - 5, y - 5, 10, 10);
} else {
// For the SMUDGE tool, blend some of the color from
// the smudgeRed, smudgeGreen, and smudgeBlue arrays
// into the pixels in a 7-by-7 block around (x,y), and
// vice versa. The effect is to smear out the color
// of pixels that are visited by the tool.
for (int i = 0; i < 7; i++) {
for (int j = 0; j < 7; j++) {
int r = y + j - 3;
int c = x + i - 3;
if (!(r < 0 || r >= h || c < 0 || c >= w || smudgeRed[i][j] == -1)) {
int curCol = OSC.getRGB(c, r);
int curRed = (curCol >> 16) & 0xFF;
int curGreen = (curCol >> 8) & 0xFF;
int curBlue = curCol & 0xFF;
int newRed = (int) (curRed * 0.7 + smudgeRed[i][j] * 0.3);
int newGreen = (int) (curGreen * 0.7 + smudgeGreen[i][j] * 0.3);
int newBlue = (int) (curBlue * 0.7 + smudgeBlue[i][j] * 0.3);
int newCol = newRed << 16 | newGreen << 8 | newBlue;
OSC.setRGB(c, r, newCol);
smudgeRed[i][j] = curRed * 0.3 + smudgeRed[i][j] * 0.7;
smudgeGreen[i][j] = curGreen * 0.3 + smudgeGreen[i][j] * 0.7;
smudgeBlue[i][j] = curBlue * 0.3 + smudgeBlue[i][j] * 0.7;
}
}
}
repaint(x - 3, y - 3, 7, 7);
}
}
g.dispose();
}
/** Start a drag operation. */
@Override
public void mousePressed(MouseEvent evt) {
startX = prevX = currentX = evt.getX();
startY = prevY = currentY = evt.getY();
dragging = true;
if (currentTool == Tool.ERASE) {
// Erase a 10-by-10 block around the starting mouse position.
Graphics g = OSC.getGraphics();
g.setColor(fillColor);
g.fillRect(startX - 5, startY - 5, 10, 10);
g.dispose();
repaint(startX - 5, startY - 5, 10, 10);
} else if (currentTool == Tool.SMUDGE) {
// Record the colors in a 7-by-7 block of pixels around the
// starting mouse position into the arrays smudgeRed,
// smudgeGreen, and smudgeBlue. These arrays hold the
// red, green, and blue components of the colors.
if (smudgeRed == null) {
// Create the arrays, if they have not already been created.
smudgeRed = new double[7][7];
smudgeGreen = new double[7][7];
smudgeBlue = new double[7][7];
}
int w = OSC.getWidth();
int h = OSC.getHeight();
int x = evt.getX();
int y = evt.getY();
for (int i = 0; i < 7; i++) {
for (int j = 0; j < 7; j++) {
int r = y + j - 3;
int c = x + i - 3;
if (r < 0 || r >= h || c < 0 || c >= w) {
// A -1 in the smudgeRed array indicates that the
// corresponding pixel was outside the canvas.
smudgeRed[i][j] = -1;
} else {
int color = OSC.getRGB(c, r);
smudgeRed[i][j] = (color >> 16) & 0xFF;
smudgeGreen[i][j] = (color >> 8) & 0xFF;
smudgeBlue[i][j] = color & 0xFF;
}
}
}
}
}
/**
* 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;
}
@Override
public void actionPerformed(ActionEvent evt) {
String command = evt.getActionCommand();
switch (command) {
case "New File":
{
OSC = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);
Graphics osg = OSC.getGraphics();
osg.setColor(fillColor);
osg.fillRect(0, 0, getWidth(), getHeight());
osg.dispose();
repaint();
break;
}
case "Open":
{
JFileChooser chooser = new JFileChooser();
FileNameExtensionFilter filter =
new FileNameExtensionFilter("JPG or PNG Images", "jpg", "png");
chooser.setFileFilter(filter);
int returnVal = chooser.showOpenDialog(null);
if (returnVal == JFileChooser.APPROVE_OPTION) {
try {
OSC = ImageIO.read(chooser.getSelectedFile());
Graphics2D g2 = (Graphics2D) OSC.getGraphics();
g2.scale((double) 640 / OSC.getWidth(), (double) 480 / OSC.getHeight());
g2.drawImage(OSC, 0, 0, OSC.getWidth(), OSC.getHeight(), null);
} catch (Exception e) {
}
}
repaint();
break;
}
case "Save":
{
JFileChooser fileDialog = new JFileChooser();
fileDialog.setSelectedFile(new File("image.PNG"));
fileDialog.setDialogTitle("Select File to be Saved");
int option = fileDialog.showSaveDialog(null);
if (option != JFileChooser.APPROVE_OPTION)
return; // User canceled or clicked the dialog’s close box.
File selectedFile = fileDialog.getSelectedFile();
if (selectedFile.exists()) { // Ask the user whether to replace the file.
int response =
JOptionPane.showConfirmDialog(
null,
"The file \""
+ selectedFile.getName()
+ "\" already exists.\nDo you want to replace it?",
"Confirm Save",
JOptionPane.YES_NO_OPTION,
JOptionPane.WARNING_MESSAGE);
if (response != JOptionPane.YES_OPTION)
return; // User does not want to replace the file.
}
try {
boolean hasFormat = ImageIO.write(OSC, "PNG", selectedFile);
if (!hasFormat) throw new Exception("PNG" + " format is not available.");
} catch (Exception e) {
JOptionPane.showMessageDialog(
null, "Sorry, an error occurred while trying to save image.");
e.printStackTrace();
}
break;
}
case "Exit":
{
System.exit(0);
}
case "Select Drawing Color...":
{
Color newColor =
JColorChooser.showDialog(AdvancedGUIEX1.this, "Select Drawing Color", currentColor);
if (newColor != null) currentColor = newColor;
break;
}
case "Fill With Color...":
{
Color newColor =
JColorChooser.showDialog(AdvancedGUIEX1.this, "Select Fill Color", fillColor);
if (newColor != null) {
fillColor = newColor;
Graphics osg = OSC.getGraphics();
osg.setColor(fillColor);
osg.fillRect(0, 0, OSC.getWidth(), OSC.getHeight());
osg.dispose();
AdvancedGUIEX1.this.repaint();
}
break;
}
case "Draw With Black":
currentColor = Color.BLACK;
break;
case "Draw With White":
currentColor = Color.WHITE;
break;
case "Draw With Red":
currentColor = Color.RED;
break;
case "Draw With Green":
currentColor = Color.GREEN;
break;
case "Draw With Blue":
currentColor = Color.BLUE;
break;
case "Draw With Yellow":
currentColor = Color.YELLOW;
break;
case "Curve":
currentTool = Tool.CURVE;
break;
case "Line":
currentTool = Tool.LINE;
break;
case "Rectangle":
currentTool = Tool.RECT;
break;
case "Oval":
currentTool = Tool.OVAL;
break;
case "Filled Rectangle":
currentTool = Tool.FILLED_RECT;
break;
case "Filled Oval":
currentTool = Tool.FILLED_OVAL;
break;
case "Smudge":
currentTool = Tool.SMUDGE;
break;
case "Erase":
currentTool = Tool.ERASE;
break;
}
}