pinboard-object Class

Summary

Provides a rectangular area in a pinboard-layout with drawing capabilities.

Package

capi

Superclasses

capi-object

Subclasses

ellipse
item-pinboard-object
image-pinboard-object
line-pinboard-object
drawn-pinboard-object
rectangle

Initargs

Accessors

pinboard-object-pinboard
pinboard-object-activep
pinboard-object-graphics-args

Description

The class pinboard-object provides a rectangular area in a pinboard-layout with drawing and highlighting capabilities. A pinboard object behaves just like a simple pane within layouts, meaning that they can be placed into rows, columns and other layouts, and that they size themselves in the same way. The main distinction is that a pinboard object is a much smaller object than a simple pane as it does not need to create a native window for itself.

Each pinboard object is placed into a pinboard layout (or into a layout itself inside a pinboard layout), and then when the pinboard layout wishes to redisplay a region of itself, it calls the function draw-pinboard-object on each of the pinboard objects that are contained in that region (in the order that they are specified as children to the layout).

The graphics-args slot allows drawing options to be set. These include the font, the background and foreground colors, and others (see graphics-state). The graphics-args are used by the built-in pinboard-object (all subclasses of pinboard-object except drawn-pinboard-object) as extra arguments in calls to drawing functions. For example, to create a filled red rectangle object, you can use:

(make-instance 
 'capi:rectangle
 :filled t :x 100 :y 100
 :visible-min-width 100
 :visible-min-height 100
 :graphics-args '(:foreground :red))

The graphics args can be accessed after creation using pinboard-object-graphics-args, and it is also possible to modify a single value using pinboard-object-graphics-arg.

When no-highlight is t, CAPI does not call draw-pinboard-object-highlighted even when the object is highlighted. Typically, the drawing function you supply (either the method draw-pinboard-object or the display-callback for drawn-pinboard-object) will do the highlight in this case, using pinboard-object-highlighted-p to check if they need to.

The geometry hints are interpreted as described for element. After creation, you can query the geometry of a pinboard-object using the functions static-layout-child-position and static-layout-child-size and static-layout-child-geometry. You can also set the geometry using cl:setf with these functions.

By default a pinboard-object does not accept the input focus.

There are a number of predefined pinboard objects provided by the CAPI. They are as follows:

The main user of pinboard objects in the CAPI is the graph pane, which uses item-pinboard-object and line-pinboard-object to display its nodes and edges respectively.

To force a pinboard object to redraw itself call redraw-pinboard-object. The redrawing may be cached and displayed at a later date.

Call the generic functions highlight-pinboard-object and unhighlight-pinboard-object to highlight a pinboard and remove its highlighting. If you want non-standard highlighting, you can implement methods for your subclass of pinboard-object.

You can test whether a whether a point or region coincides with a pinboard object by the generic functions over-pinboard-object-p and pinboard-object-overlap-p. The default methods assume a rectangle based on the geometry, which must always be the enclosing rectangle of the whole pinboard object. Therefore you only need to implement methods if your subclass of pinboard-object has a non-rectangular shape.

automatic-resize makes the pinboard object resize automatically. This has an effect only if it is placed inside a static-layout (including subclasses like pinboard-layout). The effect is that when the static-layout is resized then the pinboard object also changes its geometry.

The value of automatic-resize defines how the pinboard object's geometry changes. It must be a plist of keywords and values which match the keywords of the function set-object-automatic-resize and are interpreted in the same way.

Notes

You can also control automatic resizing of a pinboard object using set-object-automatic-resize.

Examples

(example-edit-file "capi/graphics/pinboard-test")

(example-edit-file "capi/graphics/highlight-rectangle-pinboard")

(example-edit-file "capi/graphics/circled-graph-nodes")

There are further examples in 20 Self-contained examples.

See also

pinboard-layout
draw-pinboard-object
graph-pane
highlight-pinboard-object
over-pinboard-object-p
redraw-pinboard-object
redraw-pinboard-layout
pinboard-object-overlap-p
pinboard-object-graphics-arg
set-object-automatic-resize
static-layout
unhighlight-pinboard-object
6 Laying Out CAPI Panes
12.3 Creating graphical objects