Canvas Items

The following are the types of canvas items:

• Arc: a section of an oval, given by the start angle and the length (configurations start and extent).
• BitmapItem and ImageItem: canvas items given by bitmaps and images. The image of an image item is set with the HasPhoto class, just like for some widgets.
• LineItem: a line item is given by a list of two or more points, which define a list of line segments. The segments can be joined in various ways (with the joinstyle configuration), you can draw splines (class CanvasItem.SegmentedCanvasItemSegmentedCanvasItem), and put arrows on either (or both) ends (configurations arrowshape and arrowstyle).
• Oval: an oval is given by defining its bounding box, i.e. the smallest rectangle enclosing it, using the classes HasGeometry or HasPosition and HasSize. If the bounding box is a square, the oval is a circle.
• Polygon: a polygon is given by a list of vertices. Strangely, one cannot configure the join style of the polygon, but you can configure splines.
• Rectangle: a rectangle is given by two points.
• TextItem: a text item is a text, possibly consisting of more than one line. It is an instance of HasFont. (Note that HTK curently does not support Tk's selection and insertion methods for text items; it should be easy to add, if you really require that.)
• EmbeddedCanvasWin: an embedded canvas window is a widget embedded into a canvas. All instances of class Widget can be embedded into a canvas. Note that you don't need to pack embedded widgets; they appear as soon as the embedded canvas window is created.

  
Figure 5: Canvas items: a text item, three image items, a line item, an arc and an embedded window (a button).