The Yoix^® Scripting Language

Reading returns the current cursor. Writing immediately changes the canvas's cursor to the new value. Storing STANDARD_CURSOR (the default) or NULL in cursor is special and means use the cursor assigned to the nearest component that contains the canvas and was assigned a cursor other than STANDARD_CURSOR; if no component qualifies the canvas uses DEFAULT_CURSOR.

Pan control bits:

bit 0 - mouse button 1 can be used to start panning
bit 1 - mouse button 2 can be used to start panning
bit 2 - mouse button 3 can be used to start panning
bit 3 - unused
bit 4 - SHIFT key must be held to start panning
bit 5 - CTRL key must be held to start panning
bit 6 - ALT key must be held to start panning
bit 7 - pan using copyarea otherwise full repaint

Zoom control bits:

bit 8  - unused
bit 9  - unused
bit 10 - unused
bit 11 - enable mouse wheel zooming
bit 12 - SHIFT key must be held to start zooming
bit 13 - CTRL key must be held to start zooming
bit 14 - ATL key must be held to start zooming
bit 15 - unused

Reset control bits:

bit 16 - mouse button 1 can be used for reset
bit 17 - mouse button 2 can be used for reset
bit 18 - mouse button 3 can be used for reset
bit 19 - unused
bit 20 - SHIFT key must be held to trigger reset
bit 21 - CTRL key must be held to trigger reset
bit 22 - ALT key must be held to trigger reset
bit 23 - unused

Reset control restores the default matrix for the canvas. It's sometimes convenient, but isn't always appropriate (e.g., the matrix was scaled or translated before the initial paint), so in many cases you'll use an event handler attached to a component, like a JButton, to handle resets.

When bit 7 is set automatic panning tries to use copyarea to update the canvas, otherwise a full repaint of the canvas is always used. Only set this bit if the paint() function defined in the canvas is smart and uses the clipping rectangle passed as an argument to reduce its workload because each copyarea usually generates two paint() calls (to refresh the two small rectangles uncovered by copyarea).

Swing components that provide automatic drag handling start out with a transferhandler field that is not NULL, but the automatic drag handling is not enabled until 1 is stored in dragenabled. Swing components that provide their own drag and drop event handlers currently must store NULL in transferhandler before those event handlers will start working.

import yoix.*.*;

JFrame f = {
    FlowLayout layoutmanager = {
        int hgap = 72/4;
        int vgap = 72;
    };

    Array layout = {
        new JCanvas {
            Color background = {double red = .5;};
            int   border = 72/12;
            int   state = FALSE;

            Dimension size = {
                int height = 72;
                int width = 2*72;
            };
        },
        new JCanvas {
            Color background = {double green = .5;};
            int   border = 72/12;
            int   state = TRUE;

            Dimension size = {
                int height = 72;
                int width = 72;
            };
        },

        new JCanvas {
            Color background = Color.blue;
            Dimension preferredsize = {
                int height = 36;
                int width = 72;
            };
        },
    };
};

f.visible = TRUE;
sleep(5);
f.visible = FALSE;

The next program,

import yoix.*.*;

final double SHADOW = 72.0/36;

Image att = {
    String source = "http://www.yoix.org/imgs/ATTlogo.gif";
};

JCanvas c = {
    double border = SHADOW;
    Color  background = Color.gray;
    Image  backgroundimage = att;
    int    backgroundhints = SCALE_DEFAULT;
    int    state = FALSE;

    Dimension size = {
        double width = att.size.width + 2*SHADOW;
        double height = att.size.height + 2*SHADOW;
    };

    actionPerformed(ActionEvent e) {
        printf("URL=%s\n", att.source);
    }
};

JFrame f = {
    FlowLayout layoutmanager = {
        int vgap = 72;
    };

    Array layout = {c};
};

f.visible = TRUE;
sleep(5);
exit(0);

The last program,

import yoix.*.*;

JFrame f = {
    Array layout = {
        new JCanvas {
            String tag = "$_canvas";
            Color  background = Color.white;
            //
            // SHIFT with button 1 pans and mouse wheel zooms.
            //
            int   panandzoom = 0x000811;

            Graphics graphics = {
                String font = "Lucida-plain-24";
                int    textantialiasing = TRUE;
            };

            paint(Rectangle rect) {
                graphics {          // "named block"
                    gsave();
                    translate(72, 72);
                    rotate(10);
                    moveto(0, 0);
                    show("wide");
                    moveto(0, 36);
                    scale(2, 1);
                    show("wider");
                    moveto(0, 72);
                    scale(2, 1);
                    show("widest");
                    grestore();
                }
            }
        }, CENTER,

        new JButton {
            String text = "Reset";

            actionPerformed(e) {
                root.components.$_canvas.graphics.initmatrix();
                root.components.$_canvas.repaint();
            }
        }, SOUTH,
    };
};

f.visible = TRUE;