diff options
| -rw-r--r-- | doc/busy.n | 32 |
1 files changed, 20 insertions, 12 deletions
@@ -28,7 +28,7 @@ .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME -busy \- confine pointer and keyboard events to a window sub-tree +busy \- confine pointer events to a window sub-tree .SH SYNOPSIS \fBtk busy\fR \fIwindow \fR?\fIoptions\fR? .sp @@ -44,9 +44,10 @@ busy \- confine pointer and keyboard events to a window sub-tree .BE .SH DESCRIPTION .PP -The \fBtk busy\fR command provides a simple means to block keyboard, button, -and pointer events from Tk widgets, while overriding the widget's cursor with -a configurable busy cursor. +The \fBtk busy\fR command provides a simple means to block pointer events from +Tk widgets, while overriding the widget's cursor with a configurable busy +cursor. Note this command does not prevent keyboard events from being sent to +the widgets made busy. .SH INTRODUCTION .PP There are many times in applications where you want to temporarily restrict @@ -68,8 +69,8 @@ that overrides the widget's normal cursor, providing feedback that the application (widget) is temporarily busy. .PP When a widget is made busy, the widget and all of its descendants will ignore -events. It's easy to make an entire panel of widgets busy. You can simply make -the toplevel widget (such as +pointer events. It's easy to make an entire panel of widgets busy. You can +simply make the toplevel widget (such as .QW . ) busy. This is easier and far much more efficient than recursively traversing the widget hierarchy, disabling each widget and re-configuring its cursor. @@ -240,20 +241,27 @@ widgets. .SS "KEYBOARD EVENTS" .PP When a widget is made busy, the widget is prevented from gaining the keyboard -focus by the busy window. But if the widget already had focus, it still may -received keyboard events. To prevent this, you must move focus to another -window. +focus by a user clicking on it by the busy window. But if the widget already had +focus, it still may receive keyboard events. The widget can also still receive +focus through keyboard traversal. To prevent this, you must move +focus to another window and make sure the focus can not go back to the widgets +made busy (e.g. but restricting focus to a cancel button). .PP .CS +pack [frame .frame] +pack [text .frame.text] \fBtk busy\fR hold .frame -label .dummy -focus .dummy +pack [button .cancel -text "Cancel" -command exit] +focus .cancel +bind .cancel <Tab> {break} +bind .cancel <Shift-Tab> {break} update .CE .PP The above example moves the focus from .frame immediately after invoking the \fBhold\fR so that no keyboard events will be sent to \fB.frame\fR or any of -its descendants. +its descendants. It also makes sure it's not possible to leave button +\fB.cancel\fR using the keyboard. .SH PORTABILITY .PP Note that the \fBtk busy\fR command does not currently have any effect on OSX |