canvas is used for providing drawing areas. the syntax for canvas widget is shown below −
canvas canvasname options
options
the options available for the canvas widget are listed below in the following table −
| sr.no. | syntax & description |
|---|---|
| 1 |
-background color used to set background color for widget. |
| 2 |
-closeenough distance sets the closeness of mouse cursor to a displayable item. the default is 1.0 pixel. this value may be a fraction and must be positive. |
| 3 |
-scrollregion boundingbox the bounding box for the total area of this canvas. |
| 4 |
-height number used to set height for widget. |
| 5 |
-width number sets the width for widget. |
| 6 |
-xscrollincrement size the amount to scroll horizontally when scrolling is requested. |
| 7 |
-yscrollincrement size the amount to scroll vertically when scrolling is requested. |
a simple example for canvas widget is shown below −
#!/usr/bin/wish canvas .mycanvas -background red -width 100 -height 100 pack .mycanvas
when we run the above program, we will get the following output −
widgets for drawing in canvas
the list of the available widgets for drawing in canvas is listed below −
| sr.no. | widget & description |
|---|---|
| 1 |
line
draws a line. |
| 2 |
arc
draws an arc. |
| 3 |
rectangle
draws a rectangle. |
| 4 |
oval
draws an oval. |
| 5 |
polygon
draws a polygon. |
| 6 |
text
draws a text. |
| 7 |
bitmap
draws a bitmap. |
| 8 |
image
draws an image. |
an example using different canvas widgets is shown below −
#!/usr/bin/wish
canvas .mycanvas -background red -width 200 -height 200
pack .mycanvas
.mycanvas create arc 10 10 50 50 -fill yellow
.mycanvas create line 10 30 50 50 100 10 -arrow both -fill yellow -smooth true
-splinesteps 2
.mycanvas create oval 50 50 100 80 -fill yellow
.mycanvas create polygon 50 150 100 80 120 120 100 190 -fill yellow -outline green
.mycanvas create rectangle 150 150 170 170 -fill yellow
.mycanvas create text 170 20 -fill yellow -text "hello" -font {helvetica -18 bold}
.mycanvas create bitmap 180 50 -bitmap info
when we run the above program, we will get the following output −
