Added source code

.gitignore

@@ -0,0 +1,10 @@
+*.class
+
+# Package Files #
+*.jar
+*.war
+*.ear
+
+.idea/*
+*.iml
+target/*

README.md

@@ -4,23 +4,23 @@ A rudimentary toolkit for incorporating [MacPaint](https://en.wikipedia.org/wiki
 
 ## Paint tools
 
-Tool            | Description
-----------------| -------------
-![Airbrush](icons/spraypaint.png) Airbrush       | Paints translucent color or texture onto the canvas.
-![Curve](icons/curve.png) Curve                  | Draws quadratic (Bezier) curves by clicking to specify points on the curve.
-![Eraser](icons/eraser.png) Eraser               | Removes paint from the canvas by restoring affected pixels to their fully-transparent state.
-![Fill](icons/fill.png) Fill                     | Shades an enclosed area with paint using a [flood-fill](https://en.wikipedia.org/wiki/Flood_fill) algorithm.
-![Lasso](icons/lasso.png) Lasso                  | Define a free-form selection boundary ([marching ants](https://en.wikipedia.org/wiki/Marching_ants)) for clearing or moving paint.
-![Line](icons/line.png) Line                     | Draws straight lines; hold `shift` to restrict lines to 15-degree angles.
-![Oval](icons/oval.png) Oval                     | Draws filled or outlined oval shapes; hold `shift` to constrain boundary to circle.
-![Paintbrush](icons/paintbrush.png) Paintbrush   | Draws paint on the canvas (using configurable stroke and color/texture).
-![Pencil](icons/pencil.png) Pencil               | Draws a free-form, narrow black path on the canvas.
-![Polygon](icons/polygon.png) Polygon            | Draws filled or outlined irregular polygons by clicking to specify points. Double-click to complete the polygon; press `esc` to keep only the lines visible; hold `shift` to restrict line angles to 15 degree multiples.
-![Rectangle](icons/rectangle.png) Rectangle      | Draws filled or outlined rectangles on the canvas; hold `shift` to constrain boundary to a square.
-![Round Rect](icons/roundrect.png) Round Rect    | Draws filled or outlined round-rectangles on the canvas.
-![Selection](icons/selection.png) Selection      | Define a selection rectangle ([marching ants](https://en.wikipedia.org/wiki/Marching_ants)) whose underlying graphic can be moved or cleared (press `delete`)
-![Shape](icons/shape.png) Shape                  | Draws filled or outlined regular polygons (i.e., shapes--triangles, squares, polygons, hexagons, etc.)
-![Text](icons/text.png) Text                     | Draws rasterized text (of a configurable font, size and style) on the canvas. Text remains editable until user clicks away.
+| Tool            | Description
+| ----------------| -------------
+![Airbrush](icons/spraypaint.png) | Airbrush       | Paints translucent color or texture onto the canvas.
+![Curve](icons/curve.png) | Curve                  | Draws quadratic (Bezier) curves by clicking to specify points on the curve.
+![Eraser](icons/eraser.png) | Eraser               | Removes paint from the canvas by restoring affected pixels to their fully-transparent state.
+![Fill](icons/fill.png) | Fill                     | Shades an enclosed area with paint using a [flood-fill](https://en.wikipedia.org/wiki/Flood_fill) algorithm.
+![Lasso](icons/lasso.png) | Lasso                  | Define a free-form selection boundary ([marching ants](https://en.wikipedia.org/wiki/Marching_ants)) for clearing or moving paint.
+![Line](icons/line.png) | Line                     | Draws straight lines; hold `shift` to restrict lines to 15-degree angles.
+![Oval](icons/oval.png) | Oval                     | Draws filled or outlined oval shapes; hold `shift` to constrain boundary to circle.
+![Paintbrush](icons/paintbrush.png) | Paintbrush   | Draws paint on the canvas (using configurable stroke and color/texture).
+![Pencil](icons/pencil.png) | Pencil               | Draws a free-form, narrow black path on the canvas.
+![Polygon](icons/polygon.png) | Polygon            | Draws filled or outlined irregular polygons by clicking to specify points. Double-click to complete the polygon; press `esc` to keep only the lines visible; hold `shift` to restrict line angles to 15 degree multiples.
+![Rectangle](icons/rectangle.png) | Rectangle      | Draws filled or outlined rectangles on the canvas; hold `shift` to constrain boundary to a square.
+![Round Rect](icons/roundrect.png) | Round Rect    | Draws filled or outlined round-rectangles on the canvas.
+![Selection](icons/selection.png) | Selection      | Define a selection rectangle ([marching ants](https://en.wikipedia.org/wiki/Marching_ants)) whose underlying graphic can be moved or cleared (press `delete`)
+![Shape](icons/shape.png) | Shape                  | Draws filled or outlined regular polygons (i.e., shapes--triangles, squares, polygons, hexagons, etc.)
+![Text](icons/text.png) | Text                     | Draws rasterized text (of a configurable font, size and style) on the canvas. Text remains editable until user clicks away.
 
 (There's also an "Arrow" tool that functions as a no-op that does not modify the canvas in any way.)
 
@@ -201,7 +201,7 @@ Tool Base                | Description
 
 #### How can I layer canvases atop one another, or place other UI elements (like buttons and fields) on top of the painted graphics?
 
-Place the canvas(es) and/or other UI components in a `LayeredPane`. Use the `LayeredPane` to control z-order. 
+Place the canvas(es) and/or other UI components in a `LayeredPane`. Use the `LayeredPane` to control z-order.
 
 #### What about vector graphic tools (i.e., "draw" apps)?
 

pom.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+
+    <modelVersion>4.0.0</modelVersion>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+    </properties>
+
+    <packaging>jar</packaging>
+    <groupId>com.defano</groupId>
+    <artifactId>jmonet</artifactId>
+    <version>0.0.1</version>
+
+</project>

src/main/java/com/defano/jmonet/canvas/BasicCanvas.java

@@ -0,0 +1,122 @@
+package com.defano.jmonet.canvas;
+
+import com.defano.jmonet.canvas.surface.AbstractSurface;
+import com.defano.jmonet.model.Provider;
+
+import java.awt.*;
+import java.awt.image.BufferedImage;
+
+public class BasicCanvas extends AbstractSurface implements Canvas {
+
+    private Point imageLocation = new Point(0, 0);
+    private Provider<Double> scale = new Provider<>(1.0);
+    private Provider<Integer> gridSpacing = new Provider<>(1);
+
+    private BufferedImage image;
+    private BufferedImage scratch;
+
+    public BasicCanvas() {
+        this(null);
+    }
+
+    public BasicCanvas(BufferedImage initialImage) {
+
+        if (initialImage == null) {
+            image = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB);
+        } else {
+            image = initialImage;
+        }
+
+        scratch = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_ARGB);
+    }
+
+    public void clearCanvas() {
+        Graphics2D g2 = (Graphics2D) getScratchImage().getGraphics();
+        g2.setColor(Color.WHITE);
+        g2.fillRect(0, 0, getWidth(), getHeight());
+        commit(AlphaComposite.getInstance(AlphaComposite.DST_OUT, 1.0f));
+    }
+
+    protected void overlayImage(BufferedImage source, BufferedImage destination, AlphaComposite composite) {
+
+        Graphics2D g2d = (Graphics2D) destination.getGraphics();
+        g2d.setComposite(composite);
+        g2d.drawImage(source, 0,0, null);
+        g2d.dispose();
+    }
+
+    public BufferedImage getCanvasImage() {
+        return image;
+    }
+
+    public BufferedImage getScratchImage() {
+        return scratch;
+    }
+
+    @Override
+    public void setCanvasImage(BufferedImage image) {
+        this.image = image;
+    }
+
+    @Override
+    public void setScratchImage(BufferedImage image) {
+        this.scratch = image;
+    }
+
+    public void commit() {
+        commit(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 1.0f));
+    }
+
+    /**
+     * Copies the image contents of the scratch buffer to the Canvas' image.
+     */
+    public void commit(AlphaComposite composite) {
+        BufferedImage scratchImage = getScratchImage();
+        BufferedImage canvasImage = getCanvasImage();
+
+        overlayImage(scratchImage, canvasImage, composite);
+        fireObservers(this, scratchImage, canvasImage);
+
+        clearScratch();
+        invalidateCanvas();
+    }
+
+    /**
+     * Creates a clean scratch buffer (replacing all pixels in the graphics context with transparent pixels).
+     */
+    public void clearScratch() {
+        scratch = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_ARGB);
+    }
+
+    @Override
+    public void setImageLocation(Point location) {
+        imageLocation = location;
+    }
+
+    @Override
+    public Point getImageLocation() {
+        return imageLocation;
+    }
+
+    @Override
+    public Provider<Double> getScaleProvider() {
+        return scale;
+    }
+
+    @Override
+    public void setGridSpacing(int grid) {
+        this.gridSpacing.set(grid);
+    }
+
+    @Override
+    public Provider<Integer> getGridSpacingProvider() {
+        return gridSpacing;
+    }
+
+    @Override
+    public void setScale(double scale) {
+        this.scale.set(scale);
+        invalidateCanvas();
+    }
+
+}

src/main/java/com/defano/jmonet/canvas/Canvas.java

@@ -0,0 +1,19 @@
+package com.defano.jmonet.canvas;
+
+import com.defano.jmonet.canvas.surface.PaintableSurface;
+
+import java.awt.*;
+
+public interface Canvas extends PaintableSurface {
+    boolean isVisible();
+
+    void setCursor(Cursor cursor);
+
+    void addObserver(CanvasCommitObserver observer);
+    boolean removeObserver(CanvasCommitObserver observer);
+
+    void invalidateCanvas();
+
+    void commit();
+    void commit(AlphaComposite composite);
+}

src/main/java/com/defano/jmonet/canvas/CanvasCommitObserver.java

@@ -0,0 +1,14 @@
+package com.defano.jmonet.canvas;
+
+import java.awt.image.BufferedImage;
+
+public interface CanvasCommitObserver {
+    /**
+     * Fires when an new shape or image is committed from scratch onto the canvas.
+     *
+     * @param canvas The canvas on which the commit is occurring.
+     * @param committedElement An image representing just the change being committed.
+     * @param canvasImage The resulting canvas image (including the committed change)
+     */
+    void onCommit(Canvas canvas, BufferedImage committedElement, BufferedImage canvasImage);
+}

src/main/java/com/defano/jmonet/canvas/CanvasInteractionObserver.java

@@ -0,0 +1,51 @@
+package com.defano.jmonet.canvas;
+
+import java.awt.event.*;
+
+public interface CanvasInteractionObserver extends KeyListener {
+
+    /**
+     * Invoked when the mouse button has been clicked (pressed
+     * and released) on the canvas.
+     */
+    void mouseClicked(MouseEvent e, int scaleX, int scaleY);
+
+    /**
+     * Invoked when a mouse button has been pressed on a component.
+     */
+    void mousePressed(MouseEvent e, int scaleX, int scaleY);
+
+    /**
+     * Invoked when a mouse button has been released on a component.
+     */
+    void mouseReleased(MouseEvent e, int scaleX, int scaleY);
+
+    /**
+     * Invoked when the mouse enters a component.
+     */
+    void mouseEntered(MouseEvent e, int scaleX, int scaleY);
+
+    /**
+     * Invoked when the mouse exits a component.
+     */
+    void mouseExited(MouseEvent e, int scaleX, int scaleY);
+
+    /**
+     * Invoked when a mouse button is pressed on a component and then
+     * dragged.  <code>MOUSE_DRAGGED</code> events will continue to be
+     * delivered to the component where the drag originated until the
+     * mouse button is released (regardless of whether the mouse position
+     * is within the bounds of the component).
+     * <p>
+     * Due to platform-dependent Drag&amp;Drop implementations,
+     * <code>MOUSE_DRAGGED</code> events may not be delivered during a native
+     * Drag&amp;Drop operation.
+     */
+    void mouseDragged(MouseEvent e, int scaleX, int scaleY);
+
+    /**
+     * Invoked when the mouse cursor has been moved onto a component
+     * but no buttons have been pushed.
+     */
+    void mouseMoved(MouseEvent e, int scaleX, int scaleY);
+}

src/main/java/com/defano/jmonet/canvas/JFXCanvasNode.java

@@ -0,0 +1,19 @@
+package com.defano.jmonet.canvas;
+
+import javafx.application.Platform;
+import javafx.embed.swing.SwingNode;
+
+public class JFXCanvasNode extends SwingNode {
+
+    private final BasicCanvas canvas;
+
+    public JFXCanvasNode(BasicCanvas canvas) {
+        this.canvas = canvas;
+        Platform.runLater(() -> JFXCanvasNode.super.setContent(canvas));
+    }
+
+    public Canvas getCanvas() {
+        return canvas;
+    }
+
+}