RGtk2: gdkPointerGrab – R documentation

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gdkPointerGrab

Description

Grabs the pointer (usually a mouse) so that all events are passed to this application until the pointer is ungrabbed with gdkPointerUngrab, or the grab window becomes unviewable. This overrides any previous pointer grab by this client.

Usage

gdkPointerGrab(window, owner.events = FALSE, event.mask = 0, 
    confine.to = NULL, cursor = NULL, time = "GDK_CURRENT_TIME")

Arguments

`window`	the `GdkWindow` which will own the grab (the grab window).
`owner.events`	if `FALSE` then all pointer events are reported with respect to `window` and are only reported if selected by `event.mask`. If `TRUE` then pointer events for this application are reported as normal, but pointer events outside this application are reported with respect to `window` and only if selected by `event.mask`. In either mode, unreported events are discarded.
`event.mask`	specifies the event mask, which is used in accordance with `owner.events`. Note that only pointer events (i.e. button and motion events) may be selected.
`confine.to`	If non-`NULL`, the pointer will be confined to this window during the grab. If the pointer is outside `confine.to`, it will automatically be moved to the closest edge of `confine.to` and enter and leave events will be generated as necessary.
`cursor`	the cursor to display while the grab is active. If this is `NULL` then the normal cursors are used for `window` and its descendants, and the cursor for `window` is used for all other windows.
`time`	the timestamp of the event which led to this pointer grab. This usually comes from a `GdkEventButton` struct, though `GDK_CURRENT_TIME` can be used if the time isn't known.

Details

Pointer grabs are used for operations which need complete control over mouse events, even if the mouse leaves the application. For example in GTK+ it is used for Drag and Drop, for dragging the handle in the GtkHPaned and GtkVPaned widgets, and for resizing columns in GtkCList widgets.

Note that if the event mask of an X window has selected both button press and button release events, then a button press event will cause an automatic pointer grab until the button is released. X does this automatically since most applications expect to receive button press and release events in pairs. It is equivalent to a pointer grab on the window with owner.events set to TRUE.

If you set up anything at the time you take the grab that needs to be cleaned up when the grab ends, you should handle the GdkEventGrabBroken events that are emitted when the grab ends unvoluntarily.

Value

[GdkGrabStatus] GDK_GRAB_SUCCESS if the grab was successful.

Author(s)

Derived by RGtkGen from GTK+ documentation

RGtk2

R Bindings for Gtk 2.8.0 and Above

v2.20.36

GPL

Authors

Michael Lawrence <michafla@gene.com> and Duncan Temple Lang <duncan@wald.ucdavis.edu>

Initial release