API Review RT:17407 Canvas Node

[Jim Graham]

Some targeted questions I'd like to see more reactions on (we made a 
preliminary prototype based on the HTML5 flavors in most cases, but 
we've done APIs that go either way in the past so we are flexible here):

Canvas.getGC() only keeps one instance and keeps returning it - good/bad?

Constructing a path in the GC vs. separate Path object?

drawFoo() vs. strokeFoo() for drawing the outline of something?

			...jim

On 4/18/12 3:36 PM, joe andresen wrote:
> Hello Everyone,
>
> We propose to add a Canvas node and GraphicsContext to a new
> javafx.scene.canvas package for JavaFX 2.2. The javafx.scene.canvas
> package provides a pair of classes for an immediate mode style API for
> rendering. Canvas Node works seemlessly with effects as well as
> Animation timers, and will be tightly bound to the new ImageOps API.
>
> This new API will allow HTML5 Canvas users to easily port their existing
> applications that make heavy use of the HTML5 canvas directly to JavaFX
> without the need to morph their application to fit the scenegraph model.
>
> You can Download and unzip the (preliminary) relevant docs here:
> JIRA: http://javafx-jira.kenai.com/browse/RT-17407
>
> Note that the docs are a work in progress but should be enough for API
> Review. (Also, Jira will be down Thursday 4/19 at 1400 PDT for a while).
>
> A list of the the methods for Canvas and GraphicsContext are listed below.
>
> Canvas:
>
> GraphicsContext getGraphicsContext2D()
> double getHeight()
> double getWidth()
> DoubleProperty heightProperty()
> void setHeight(double value)
> void setWidth(double value)
> DoubleProperty widthProperty()
>
> GraphicsContext:
> void appendSVGPath(java.lang.String svgpath)
> void applyEffect(Effect e)
> void arc(double centerX, double centerY, double radiusX, double radiusY,
> double startAngle, double length)
> void arcTo(double x1, double y1, double x2, double y2, double radius)
> void beginPath()
> void bezierCurveTo(double xc1, double yc1, double xc2, double yc2,
> double x1, double y1)
> void clearRect(double x, double y, double w, double h)
> void clip()
> void closePath()
> void drawArc(double x, double y, double w, double h, double startAngle,
> double arcExtent, ArcType closure)
> void drawImage(Image img, double x, double y)
> void drawImage(Image img, double x, double y, double w, double h)
> void drawImage(Image img, double sx, double sy, double sw, double sh,
> double dx, double dy, double dw, double dh)
> void drawLine(double x1, double y1, double x2, double y2)
> void drawOval(double x, double y, double w, double h)
> void drawPolygon(double[] xPoints, double[] yPoints, int nPoints)
> void drawPolyline(double[] xPoints, double[] yPoints, int nPoints)
> void drawRoundRect(double x, double y, double w, double h, double
> arcWidth, double arcHeight)
> void fill()
> void fillArc(double x, double y, double w, double h, double startAngle,
> double arcExtent, ArcType closure)
> void fillOval(double x, double y, double w, double h)
> void fillPolygon(double[] xPoints, double[] yPoints, int nPoints)
> void fillRect(double x, double y, double w, double h)
> void fillRoundRect(double x, double y, double w, double h, double
> arcWidth, double arcHeight)
> void fillText(java.lang.String text, double x, double y)
> void fillText(java.lang.String text, double x, double y, double maxWidth)
> Canvas getCanvas()
> boolean isPointInPath(double x, double y)
> void lineTo(double x1, double y1)
> double measureText(java.lang.String text)
> void moveTo(double x0, double y0)
> void putImageData(GraphicsContext.ImageData imagedata, double dx, double
> dy)
> void putImageData(GraphicsContext.ImageData imagedata, double dx, double
> dy, double dirtyX, double dirtyY, double dirtyWidth, double dirtyHeight)
> void quadraticCurveTo(double xc, double yc, double x1, double y1)
> void rect(double x, double y, double w, double h)
> void restore()
> void rotate(double degrees)
> void save()
> void scale(double x, double y)
> void setEffect(Effect e)
> void setFill(Paint p)
> void setFont(Font f)
> void setGlobalAlpha(double alpha)
> void setGlobalCompositeOperation(GraphicsContext.CompositeOperation op)
> void setLineCap(StrokeLineCap cap)
> void setLineJoin(StrokeLineJoin join)
> void setLineWidth(double lw)
> void setMiterLimit(double ml)
> void setStroke(Paint p)
> void setTextAlign(TextAlignment align)
> void setTextBaseline(VPos baseline)
> void setTransform(double mxx, double myx, double mxy, double myy, double
> mxt, double myt)
> void stroke()
> void strokeRect(double x, double y, double w, double h)
> void strokeText(java.lang.String text, double x, double y)
> void strokeText(java.lang.String text, double x, double y, double maxWidth)
> void transform(double mxx, double myx, double mxy, double myy, double
> mxt, double myt)
> void translate(double x, double y)