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| author | marc_culler <marc.culler@gmail.com> | 2023-11-23 20:25:06 (GMT) |
|---|---|---|
| committer | marc_culler <marc.culler@gmail.com> | 2023-11-23 20:25:06 (GMT) |
| commit | 014459077ba67c7477c4392ceb0f3525311b79d8 (patch) | |
| tree | 94735c29e8fb7fb6364d70205e2b03d6f75a25f8 /library/tk.tcl | |
| parent | 35f3b55d406eb50ce5da2d70ff50cba959f1f139 (diff) | |
| download | tk-014459077ba67c7477c4392ceb0f3525311b79d8.zip tk-014459077ba67c7477c4392ceb0f3525311b79d8.tar.gz tk-014459077ba67c7477c4392ceb0f3525311b79d8.tar.bz2 | |
Support smooth scrolling of Canvas widgets and demonstrate it in the simple scrollable canvas demo.
Diffstat (limited to 'library/tk.tcl')
| -rw-r--r-- | library/tk.tcl | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/library/tk.tcl b/library/tk.tcl index 0bb49eb..1345fbf 100644 --- a/library/tk.tcl +++ b/library/tk.tcl @@ -844,6 +844,19 @@ if {[tk windowingsystem] eq "x11"} { if {$::ttk::library ne ""} { uplevel \#0 [list source -encoding utf-8 $::ttk::library/ttk.tcl] } + +# Helper for smooth scrolling of Canvas widgets +proc ::tk::CanvasScrollByPixels {canvas deltaX deltaY} { + set width [expr {1.0 * [$canvas cget -width]}] + set height [expr {1.0 * [$canvas cget -height]}] + set X [lindex [$canvas xview] 0] + set Y [lindex [$canvas yview] 0] + set x [expr {$X - $deltaX / $width}] + set y [expr {$Y - $deltaY / $height}] + $canvas xview moveto $x + $canvas yview moveto $y +} + # Local Variables: # mode: tcl |