Node:frame, Next:, Previous:scrollbar, Up:Widget Creation


A frame widget does not do anything by itself except reserve an area of the display. Although this does not seem to have much purpose, it is a very important widget. It is a container widget; that is, it is used to group together collections of other widgets into logical groups. For example, a row of buttons may be grouped into a frame, then as the frame is manipulated so will the widgets displayed inside it. A frame widget can also be used to create large areas of color inside another container widget (such as another frame widget or a toplevel widget).

An example of the use of a frame widget as a container:

canvas .c -background red
frame .f
button .b1 -text button1
button .b2 -text button2
button .b3 -text button3
button .b4 -text button4
button .b5 -text button5
pack .b1 .b2 .b3 .b4 .b5 -in .f -side left
pack .c -side top -fill both -expand 1
pack .f -side bottom

which specifies that there are two main widgets a canvas named .c and a frame named .f. There are also 5 buttons, .b1 through .b5. The buttons are displayed inside the frame. Then then the canvas is displayed at the top of the main window and the frame is displayed at the bottom. As the frame is displayed at the bottom, then so will the buttons because they are displayed inside the frame.

(The pack command causes the widgets to be handled for display by the packer geometry manager. The -fill and -expand 1 options to pack for .c tell the display manager that if the window is resized then the canvas is to expand to fill most of the window. You will learn about geometry managers later in the Geometry Managers section.)