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|
<!DOCTYPE html>
<html>
<head>
<title>Commands Related to Mouse Wheel and
<code><b><TouchpadScroll></b></code> Event Handling</title>
<meta name="Author" content="Csaba Nemethi">
<meta name="Keywords" content=
"mouse wheel event, binding, event handling, scrolling, scrollable widget container, focus">
<link rel="stylesheet" type="text/css" href="stylesheet.css">
</head>
<body>
<div>
<h1>Commands Related to Mouse Wheel and
<code><b><TouchpadScroll></b></code> Event Handling</h1>
<h2>For Scrollutil Version 2.4</h2>
<h3>by</h3>
<h2>Csaba Nemethi</h2>
<address>
<a href="mailto:csaba.nemethi@t-online.de">csaba.nemethi@t-online.de</a>
</address>
</div>
<hr>
<h2 id="contents">Contents</h2>
<ul>
<li><a href="#add">The
<code><b>scrollutil::addMouseWheelSupport</b></code> Command</a></li>
<li><a href="#create">The
<code><b>scrollutil::createWheelEventBindings</b></code> Command</a></li>
<li><a href="#enable">The
<code><b>scrollutil::enableScrollingByWheel</b></code> Command</a></li>
<li><a href="#disable">The
<code><b>scrollutil::disableScrollingByWheel</b></code> Command</a></li>
<li><a href="#adapt">The
<code><b>scrollutil::adaptWheelEventHandling</b></code> Command</a></li>
<li><a href="#setFocusCkWin">The
<code><b>scrollutil::setFocusCheckWindow</b></code> Command</a></li>
<li><a href="#focusCkWin">The
<code><b>scrollutil::focusCheckWindow</b></code> Command</a></li>
</ul>
<div>
<p><a href="index.html">Start page</a></p>
</div>
<hr>
<h2 id="add">The <code><b>scrollutil::addMouseWheelSupport</b></code>
Command</h2>
<dl>
<dt><b>NAME</b></dt>
<dd><code>scrollutil::addMouseWheelSupport</code> – Add mouse wheel
event support</dd>
<dt class="tm"><b>SYNOPSIS</b></dt>
<dd>
<pre>
<b>scrollutil::addMouseWheelSupport</b> <i>tag</i> ?<i>axes</i>?
</pre>
</dd>
<dt><b>REQUIRED TK VERSION</b></dt>
<dd>8.4 or higher.</dd>
<dt class="tm"><b>DESCRIPTION</b></dt>
<dd>Adds mouse wheel and <code><b><TouchpadScroll></b></code> event
support to the widgets having the specified binding tag by creating
bindings for the mouse wheel and <code><b><TouchpadScroll></b></code>
events along the axes given by the optional <code><i>axes</i></code>
argument, which must be <code>xy</code> (the default, meaning both the x
and y axes), <code>x</code> (meaning the x axis only), or <code>y</code>
(meaning the y axis only). The binding scripts created by this
command will scroll the window given by the <code><b>%W</b></code> event
field with the aid of the <code><b>xview scroll</b> <i>number</i>
<b>units</b></code> and <code><b>yview scroll</b> <i>number</i>
<b>units</b></code> subcommands of the associated Tcl command.</dd>
<dd class="tm"><b>REMARK 1:</b> If <code><i>tag</i></code> is the
path name of a window then the binding scripts created by this command are
terminated by an invocation of the <code><b>break</b></code> command, in
order to prevent the processing of the mouse wheel or
<code><b><TouchpadScroll></b></code> events by further binding
scripts. For example, if <code><i>tag</i></code> is the path
name of a text widget then the terminating <code><b>break</b></code>
command makes sure that the mouse wheel or
<code><b><TouchpadScroll></b></code> events will not
<i>additionally</i> be processed by the class bindings (associated with the
binding tag <code><b>Text</b></code>), which in Tk 8.5 and later trigger a
scrolling by <i>pixels</i>, unlike the bindings created by this command,
which scroll the widget by <i>units</i> (i.e., lines and characters).</dd>
<dd class="tm"><b>REMARK 2:</b> The canvas widget has no built-in
bindings, but you can use this command to add mouse wheel and
<code><b><TouchpadScroll></b></code> event support to the widget
class <code><b>Canvas</b></code> or individual canvas widgets.</dd>
<dd class="tm">
<b>REMARK 3:</b> <i>In Tk versions prior to 8.7a4</i>, the set of
mouse wheel events depends on the windowing system:
<ul>
<li class="tm">The mouse wheel events along the vertical axis are
<code><b><MouseWheel></b></code> on
Windows, <code><b><MouseWheel></b></code> and
<code><b><Option-MouseWheel></b></code> on Mac OS X/11+, and
<code><b><MouseWheel></b></code>,
<code><b><Button-4></b></code> and
<code><b><Button-5></b></code> on X11 (where
<code><b><MouseWheel></b></code> is not triggered by the X
server, but can be produced using <code><b>event
generate</b></code>).</li>
<li class="tm">The mouse wheel events along the horizontal axis are
<code><b><Shift-MouseWheel></b></code> on
Windows, <code><b><Shift-MouseWheel></b></code> and
<code><b><Shift-Option-MouseWheel></b></code> on Mac OS X/11+,
and <code><b><Shift-MouseWheel></b></code>,
<code><b><Shift-Button-4></b></code> and
<code><b><Shift-Button-5></b></code> on X11 (where
<code><b><Shift-MouseWheel></b></code> is not triggered by the X
server, but can be produced using <code><b>event
generate</b></code>). On X11, when using Tk 8.7a3, there are two
more mouse wheel events along the horizontal axis:
<code><b><Button-6></b></code> and
<code><b><Button-7></b></code>, which are handled just like
<code><b><Shift-Button-4></b></code> and
<code><b><Shift-Button-5></b></code>, respectively. These
events are commonly triggered by left/right tilting the scroll wheel of
a mouse having one or two additional (thumb) buttons. (In Tk
versions 8.6.x, with x >= 10, left/right tilting the scroll wheel of
such a mouse gives rise to <code><b><Shift-MouseWheel></b></code>
events on Windows and Mac OS X/11+, and to
<code><b><Shift-Button-4></b></code> and
<code><b><Shift-Button-5></b></code> events on X11.)</li>
</ul>
<p><b>REMARK 4:</b> <i>In Tk versions 8.7a4 and later</i>, the set
of mouse wheel events is the same on all windowing systems:</p>
<ul>
<li class="tm">The mouse wheel events along the vertical axis are
<code><b><MouseWheel></b></code> and
<code><b><Option-MouseWheel></b></code>, where the
<code><b>Option</b></code> modifier is bound to the <code>Option</code>
key on Mac OS X/11+ and to the <code>Alt</code> key on Windows and
X11.</li>
<li class="tm">The mouse wheel events along the horizontal axis are
<code><b><Shift-MouseWheel></b></code> and
<code><b><Shift-Option-MouseWheel></b></code>, where the
<code><b>Option</b></code> modifier is bound to the <code>Option</code>
key on Mac OS X/11+ and to the <code>Alt</code> key on Windows and
X11. In these Tk versions, left/right tilting the scroll wheel of
a mouse having one or two additional (thumb) buttons gives rise to
<code><b><Shift-MouseWheel></b></code> (and
<code><b><Shift-Option-MouseWheel></b></code>) events on all
windowing systems.</li>
</ul>
</dd>
<dt class="tm"><b>KEYWORDS</b></dt>
<dd>mouse wheel event, binding, scrolling</dd>
</dl>
<div>
<p><a href="#contents">Contents</a> <a href=
"index.html">Start page</a></p>
</div>
<hr>
<h2 id="create">The <code><b>scrollutil::createWheelEventBindings</b></code>
Command</h2>
<dl>
<dt><b>NAME</b></dt>
<dd><code>scrollutil::createWheelEventBindings</code> – Create mouse
wheel event bindings</dd>
<dt class="tm"><b>SYNOPSIS</b></dt>
<dd>
<pre>
<b>scrollutil::createWheelEventBindings</b> ?<i>tag</i> <i>tag</i> ...?
</pre>
</dd>
<dt><b>REQUIRED TK VERSION</b></dt>
<dd>8.4 or higher on X11 and Mac OS X/11+; 8.6b2 or later on Windows.</dd>
<dt class="tm"><b>DESCRIPTION</b></dt>
<dd>Creates mouse wheel and <code><b><TouchpadScroll></b></code>
event bindings for the specified binding tags such that if the widget under
the pointer is (a descendant of) one of the scrollable widget containers
having the same toplevel as the widget and registered via <code><b><a href=
"#enable">scrollutil::enableScrollingByWheel</a></b></code> then these
events will trigger a scrolling of that widget container. In case of
several nested registered scrollable widget containers fulfilling these
conditions the innermost one will be scrolled. Each
<code><i>tag</i></code> argument must be <code><b>all</b></code> or the
path name of an existing toplevel widget (including
<code><b>.</b></code>).</dd>
<dd class="tm"><b>REMARK:</b> The reason for restricting the
<code><i>tag</i></code> arguments to <code><b>all</b></code> and path names
of existing toplevel widgets rather than supporting also tags like
<code>"Scrollableframe"</code> (for scrollutil::scrollableframe),
<code>"BwScrollableFrame"</code> (for BWidget ScrollableFrame) or
<code>"Scrolledframe"</code> (for iwidgets::scrolledframe) is that the
mouse wheel and <code><b><TouchpadScroll></b></code> events should
trigger a scrolling of the widget container under the pointer not only if
the widget under the pointer is the widget container itself but also if it
is a descendant of the latter (recall that for each window, the path name
of its nearest toplevel ancestor and the tag <code><b>all</b></code> are
contained in the window's default list of binding tags).</dd>
<dt class="tm"><b>KEYWORDS</b></dt>
<dd>mouse wheel event, binding, scrolling, scrollable widget container</dd>
</dl>
<div>
<p><a href="#contents">Contents</a> <a href=
"index.html">Start page</a></p>
</div>
<hr>
<h2 id="enable">The <code><b>scrollutil::enableScrollingByWheel</b></code>
Command</h2>
<dl>
<dt><b>NAME</b></dt>
<dd><code>scrollutil::enableScrollingByWheel</code> – Register
scrollable widget containers for scrolling by the mouse wheel</dd>
<dt class="tm"><b>SYNOPSIS</b></dt>
<dd>
<pre>
<b>scrollutil::enableScrollingByWheel</b> ?<i>scrollableWidgetContainer</i> <i>scrollableWidgetContainer</i> ...?
</pre>
</dd>
<dt><b>REQUIRED TK VERSION</b></dt>
<dd>8.4 or higher on X11 and Mac OS X/11+; 8.6b2 or later on Windows.</dd>
<dt class="tm"><b>DESCRIPTION</b></dt>
<dd>Adds the specified scrollable widget containers to the internal list of
widget containers that are registered for scrolling by the mouse wheel and
<code><b><TouchpadScroll></b></code> event bindings created by the
<code><b><a href=
"#create">scrollutil::createWheelEventBindings</a></b></code> command.</dd>
<dd class="tm"><b>REMARK 1:</b> When a scrollable widget container
whose path name was passed to this command gets destroyed, it is
automatically removed from the above-mentioned internal list of registered
widget containers.</dd>
<dd class="tm"><b>REMARK 2:</b> The <code><b><a href=
"scrollableframe.html">scrollutil::scrollableframe</a></b></code> command
automatically invokes this command for the scrollableframe widget it
creates.</dd>
<dt class="tm"><b>KEYWORDS</b></dt>
<dd>mouse wheel event, binding, scrolling, scrollable widget container</dd>
</dl>
<div>
<p><a href="#contents">Contents</a> <a href=
"index.html">Start page</a></p>
</div>
<hr>
<h2 id="disable">The <code><b>scrollutil::disableScrollingByWheel</b></code>
Command</h2>
<dl>
<dt><b>NAME</b></dt>
<dd><code>scrollutil::disableScrollingByWheel</code> – Deregister
scrollable widget containers for scrolling by the mouse wheel</dd>
<dt class="tm"><b>SYNOPSIS</b></dt>
<dd>
<pre>
<b>scrollutil::disableScrollingByWheel</b> ?<i>scrollableWidgetContainer</i> <i>scrollableWidgetContainer</i> ...?
</pre>
</dd>
<dt><b>REQUIRED TK VERSION</b></dt>
<dd>8.4 or higher on X11 and Mac OS X/11+; 8.6b2 or later on Windows.</dd>
<dt class="tm"><b>DESCRIPTION</b></dt>
<dd>Removes the specified scrollable widget containers from the internal
list of widget containers that are registered for scrolling by the mouse
wheel and <code><b><TouchpadScroll></b></code> event bindings created
by the <code><b><a href=
"#create">scrollutil::createWheelEventBindings</a></b></code> command.</dd>
<dt class="tm"><b>KEYWORDS</b></dt>
<dd>mouse wheel event, binding, scrolling, scrollable widget container</dd>
</dl>
<div>
<p><a href="#contents">Contents</a> <a href=
"index.html">Start page</a></p>
</div>
<hr>
<h2 id="adapt">The <code><b>scrollutil::adaptWheelEventHandling</b></code>
Command</h2>
<dl>
<dt><b>NAME</b></dt>
<dd><code>scrollutil::adaptWheelEventHandling</code> – Adapt mouse
wheel event handling</dd>
<dt class="tm"><b>SYNOPSIS</b></dt>
<dd>
<pre>
<b>scrollutil::adaptWheelEventHandling</b> ?<b>-ignorefocus</b>? ?<i>widget</i> <i>widget</i> ...?
</pre>
</dd>
<dt><b>REQUIRED TK VERSION</b></dt>
<dd>8.4 or higher on X11 and Mac OS X/11+; 8.6b2 or later on Windows.</dd>
<dt class="tm"><b>DESCRIPTION</b></dt>
<dd>If the optional <code><b>-ignorefocus</b></code> switch is <i>not</i>
present then, for each <code><i>widget</i></code> argument, the command
performs the following actions:</dd>
<dd class="tm">
<ul>
<li>
If <code><i>widget</i></code> is the path name of a <a href=
"https://www.nemethi.de/tablelist/">tablelist</a> widget then it sets
the latter's <code><b>-xmousewheelwindow</b></code> and
<code><b>-ymousewheelwindow</b></code> options to the path name of
the containing toplevel window, provided that the Tablelist version
is 6.4 or later (for earlier Tablelist versions the command silently
ignores any tablelist widget passed to it as argument). As a
result, a mouse wheel or <code><b><TouchpadScroll></b></code>
event over the tablelist's body or edit window (more precisely, a
mouse wheel or <code><b><TouchpadScroll></b></code> event sent
to any component of the tablelist having the binding tag
<code><b>TablelistBody</b></code> or
<code><b>TablelistEdit</b></code>) will be handled as follows:
<ul class="tm">
<li>If the focus is inside the tablelist widget then the event will
scroll the tablelist or its edit window and no further processing
of the event will take place.</li>
<li class="tm">If the focus is outside the tablelist widget then no
scrolling of the tablelist's body or edit window will happen.
Instead, the event will be redirected to the containing toplevel
window via <code><b>event generate</b></code>. This in
turn will trigger a scrolling of the (innermost) widget container
that is an ancestor of <code><i>widget</i></code> and has the same
toplevel (if there is such a scrollable widget container), provided
that the path name of the containing toplevel widget or the binding
tag <code><b>all</b></code> was passed to the <code><b><a href=
"#create">scrollutil::createWheelEventBindings</a></b></code>
command and this widget container was registered for scrolling via
<code><b><a href=
"#enable">scrollutil::enableScrollingByWheel</a></b></code>.</li>
</ul>
</li>
<li class="tm">
Otherwise it locates the (first) binding tag that has mouse wheel or
<code><b><TouchpadScroll></b></code>
event bindings and is different from both the path name of the
containing toplevel window and <code><b>all</b></code>. If the
search for this tag was successful then the command modifies the
widget's list of binding tags by prepending the tag
<code><b>WheeleventRedir</b></code> and appending the tag
<code><b>WheeleventBreak</b></code> to this binding tag. As a
result, a mouse wheel or <code><b><TouchpadScroll></b></code>
event sent to this widget will be handled as follows:
<ul class="tm">
<li>If the focus is on or inside the window
<code>[<b><a href="#focusCkWin">focusCheckWindow</a></b>
<i>widget</i>]</code> then the event will be handled by the
binding script associated with this tag and no further processing
of the event will take place.</li>
<li class="tm">If the focus is outside the window
<code>[<b>focusCheckWindow</b> <i>widget</i>]</code> then the
event will be redirected to the containing toplevel window
via <code><b>event generate</b></code> rather than
being handled by the binding script associated with the
above-mentioned tag. This in turn will trigger a scrolling of
the (innermost) widget container that is an ancestor of
<code><i>widget</i></code> and has the same toplevel (if there is
such a scrollable widget container), provided that the path name of
the containing toplevel widget or the binding tag
<code><b>all</b></code> was passed to the <code><b><a href=
"#create">scrollutil::createWheelEventBindings</a></b></code>
command and this widget container was registered for scrolling via
<code><b><a href=
"#enable">scrollutil::enableScrollingByWheel</a></b></code>.</li>
</ul>
</li>
</ul>
</dd>
<dd class="tm">If the <code><b>-ignorefocus</b></code> option is specified
then, for each <code><i>widget</i></code> argument, the command performs
the following actions:</dd>
<dd class="tm">
<ul>
<li>If <code><i>widget</i></code> is the path name of a <a href=
"https://www.nemethi.de/tablelist/">tablelist</a> widget then it resets
the latter's <code><b>-xmousewheelwindow</b></code> and
<code><b>-ymousewheelwindow</b></code> options to <code>""</code>,
provided that the Tablelist version is 6.4 or later (for earlier
Tablelist versions the command silently ignores any tablelist widget
passed to it as argument). As a result, if the Tablelist version
is 6.16 or later, a mouse wheel or
<code><b><TouchpadScroll></b></code> event over the tablelist's
body or edit window will scroll the tablelist or its edit window and no
further processing of the event will take place.</li>
<li class="tm">Otherwise it locates the (first) binding tag that has
mouse wheel or <code><b><TouchpadScroll></b></code> event
bindings and is different from both the path name of the containing
toplevel window and <code><b>all</b></code>. If the search for
this tag was successful then the command modifies the widget's list of
binding tags by appending the tag <code><b>WheeleventBreak</b></code>
to this binding tag. As a result, a mouse wheel or
<code><b><TouchpadScroll></b></code> event sent to this widget
will be handled by the binding script associated with this tag and no
further processing of the event will take place.</li>
</ul>
</dd>
<dd class="tm"><b>REMARK 1:</b> This command is designed to be
invoked for widgets that have mouse wheel or
<code><b><TouchpadScroll></b></code> event bindings and are
descendants of a scrollable widget container. The Tk and tile widgets
having class bindings for mouse wheel and
<code><b><TouchpadScroll></b></code> events are: listbox, text, Tk
core scrollbar, ttk::scrollbar, ttk::combobox, ttk::spinbox, ttk::notebook,
and ttk::treeview. Examples of widgets with binding tags other than
their class names that have mouse wheel and
<code><b><TouchpadScroll></b></code> event bindings are ctext and
tablelist widgets, as well as the entry components of <a href=
"https://www.nemethi.de/mentry/">mentry</a> widgets of type
<code>"Date"</code>, <code>"Time"</code>, <code>"DateTime"</code>,
<code>"IPAddr"</code>, and <code>"IPv6Addr"</code> (for Mentry versions 3.2
and above). (In case of a ctext widget <code><i>w</i></code>, the
binding tags mentioned in the description above refer to the widget's main
text widget child <code><i>w</i>.t</code> rather than to the widget
itself.)</dd>
<dd class="tm"><b>REMARK 2:</b> The mouse wheel event class bindings
for the Tk core scrollbar on Windows and X11 were added in Tk 8.6.
Prior to this Tk version there were such bindings only for the windowing
system <code><b>aqua</b></code> on the Macintosh. Scrollutil
eliminates this discrepancy by automatically creating the
<code><b>Scrollbar</b></code> class bindings for mouse wheel events on
Windows and X11. Note also that in Tk versions prior to 8.7a4 the
ttk::scrollbar widget had no <i>built-in</i> class bindings for mouse wheel
events, but Scrollutil automatically creates the missing bindings by
copying the mouse wheel event bindings of the widget class
<code><b>Scrollbar</b></code> to the binding tag
<code><b>TScrollbar</b></code>.</dd>
<dd class="tm"><b>REMARK 3:</b> As mentioned above, Tk core scrollbar
and ttk::scrollbar widgets have class bindings for mouse wheel and
<code><b><TouchpadScroll></b></code> events, hence this command
should be invoked for them in case they are descendants of a scrollable
widget container. Since this task can become tedious, Scrollutil
makes sure that if you pass a widget to this command and that widget is
embedded into a <a href="scrollarea.html">scrollarea</a> via the latter's
<code><b><a href="scrollarea.html#setwidget">setwidget</a></b></code>
subcommand, then this command will automatically be invoked for the
scrollbars of that scrollarea, too.</dd>
<dd class="tm"><b>REMARK 4:</b> Without the
<code><b>-ignorefocus</b></code> option, when handling a mouse wheel or
<code><b><TouchpadScroll></b></code> event sent to a Tk core or tile
scrollbar whose path name was passed to this command, if the focus is on or
inside the associated widget then the event will be processed by the
scrollbar rather than being redirected to the containing toplevel, just as
if the focus were on the scrollbar itself.</dd>
<dd class="tm"><b>REMARK 5:</b> The mouse wheel event class bindings
for the ttk::notebook widget were added in Tk 8.7a4, but Scrollutil
automatically creates them for all Tk versions starting with 8.4.
These bindings implement the navigation between the tabs of a ttk::notebook
or <a href="scrollednotebook.html">scrollutil::scrollednotebook</a> widget
via the mouse wheel.</dd>
<dd class="tm"><b>REMARK 6:</b> Invoking this command for widgets
that have mouse wheel or <code><b><TouchpadScroll></b></code> event
bindings and are descendants of a scrollable widget container is essential
for a user-friendly mouse wheel and
<code><b><TouchpadScroll></b></code> event handling in scrollable
widget containers. Without this step the mouse wheel and
<code><b><TouchpadScroll></b></code> events would scroll both the
listbox, text, ttk::treeview, or tablelist widget under the pointer
<i>and</i> the widget container to whose descendants the latter belongs, or
they would select the next/previous value in the ttk::combobox or
ttk::spinbox under the pointer <i>in addition to</i> scrolling the widget
container.</dd>
<dd class="tm"><b>REMARK 7:</b> The recommended invocation of this
command is without the <code><b>-ignorefocus</b></code> option, because it
significantly reduces the probability that the user will inadvertently
scroll a window within a widget container containing many scrollable
widgets.</dd>
<dt class="tm"><b>KEYWORDS</b></dt>
<dd>mouse wheel event, binding, event handling, scrolling, scrollable
widget container, focus</dd>
</dl>
<div>
<p><a href="#contents">Contents</a> <a href=
"index.html">Start page</a></p>
</div>
<hr>
<h2 id="setFocusCkWin">The
<code><b>scrollutil::setFocusCheckWindow</b></code> Command</h2>
<dl>
<dt><b>NAME</b></dt>
<dd><code>scrollutil::setFocusCheckWindow</code> – Set the "focus
check window"</dd>
<dt class="tm"><b>SYNOPSIS</b></dt>
<dd>
<pre>
<b>scrollutil::setFocusCheckWindow</b> <i>widget</i> ?<i>widget</i> ...? <i>otherWidget</i>
</pre>
</dd>
<dt><b>REQUIRED TK VERSION</b></dt>
<dd>8.4 or higher on X11 and Mac OS X/11+; 8.6b2 or later on Windows.</dd>
<dt class="tm"><b>DESCRIPTION</b></dt>
<dd>For each <code><i>widget</i></code> argument, the command sets the
associated "focus check window" to <code><i>otherWidget</i></code>.
This is the window to be used in the binding scripts for the tag
<code><b><a href="#adapt">WheeleventRedir</a></b></code> instead of the
widget when checking whether the focus is on/inside or outside that
window. For each <code><i>widget</i></code> argument,
<code><i>otherWidget</i></code> must be an ancestor of or identical to
<code><i>widget</i></code>.</dd>
<dd class="tm"><b>REMARK 1:</b> When a widget whose path name was
passed to this command as one of its <code><i>widget</i></code> arguments
gets destroyed, the association between the widget and its "focus check
window" is automatically removed.</dd>
<dd class="tm"><b>REMARK 2:</b> This command comes in handy if for
some widgets you want to make the focus check within the binding scripts
for the tag <code><b>WheeleventRedir</b></code> less restrictive. For
example, if the widget under the pointer is an entry component of a
<a href="https://www.nemethi.de/mentry/">mentry</a> <code><i>me</i></code>
of type <code>"Date"</code>, <code>"Time"</code>, <code>"DateTime"</code>,
<code>"IPAddr"</code>, or <code>"IPv6Addr"</code> and the focus is on any
of its siblings, then the mouse wheel and
<code><b><TouchpadScroll></b></code> events sent to this entry should
be handled by the entry widget itself rather than scrolling the widget
container that is an ascendant of the mentry. You can achieve this by
invoking</dd>
<dd>
<blockquote>
<pre>
set entryList [$me <a href=
"https://www.nemethi.de/mentry/mentryWidget.html#entries">entries</a>]
eval <a href="#adapt">scrollutil::adaptWheelEventHandling</a> $entryList
eval <span class="red">scrollutil::setFocusCheckWindow</span> $entryList [list $me]
</pre>
</blockquote>
</dd>
<dd>With Tcl/Tk 8.5 or above, you can use the more compact form</dd>
<dd>
<blockquote>
<pre>
set entryList [$me <a href=
"https://www.nemethi.de/mentry/mentryWidget.html#entries">entries</a>]
<a href="#adapt">scrollutil::adaptWheelEventHandling</a> {*}$entryList
<span class="red">scrollutil::setFocusCheckWindow</span> {*}$entryList $me
</pre>
</blockquote>
</dd>
<dd class="tm"><b>REMARK 3:</b> As a similar example, suppose that
<code><i>ss</i></code> is a <a href="scrollsync.html">scrollsync</a>
widget that was populated via its <code><b><a href=
"scrollsync.html#setwidgets">setwidgets</a></b></code> subcommand with
child widgets. Then, if the widget under the pointer is one of these
children and the focus is on any of the other children passed to that
subcommand, then the mouse wheel and
<code><b><TouchpadScroll></b></code> events sent to the child under
the pointer should be handled by that child widget itself rather than
scrolling the widget container that is an ascendant of the
scrollsync. You can achieve this with the following code:</dd>
<dd>
<blockquote>
<pre>
set widgetList [$ss <a href="scrollsync.html#widgets">widgets</a>]
eval <a href="#adapt">scrollutil::adaptWheelEventHandling</a> $widgetList
eval <span class="red">scrollutil::setFocusCheckWindow</span> $widgetList [list $ss]
</pre>
</blockquote>
</dd>
<dd>Again, with Tcl/Tk 8.5 or above, you can use the more compact form</dd>
<dd>
<blockquote>
<pre>
set widgetList [$ss <a href="scrollsync.html#widgets">widgets</a>]
<a href="#adapt">scrollutil::adaptWheelEventHandling</a> {*}$widgetList
<span class="red">scrollutil::setFocusCheckWindow</span> {*}$widgetList $ss
</pre>
</blockquote>
</dd>
<dt class="tm"><b>KEYWORDS</b></dt>
<dd>binding, focus, "focus check window"</dd>
</dl>
<div>
<p><a href="#contents">Contents</a> <a href=
"index.html">Start page</a></p>
</div>
<hr>
<h2 id="focusCkWin">The <code><b>scrollutil::focusCheckWindow</b></code>
Command</h2>
<dl>
<dt><b>NAME</b></dt>
<dd><code>scrollutil::focusCheckWindow</code> – Query the "focus
check window"</dd>
<dt class="tm"><b>SYNOPSIS</b></dt>
<dd>
<pre>
<b>scrollutil::focusCheckWindow</b> <i>widget</i>
</pre>
</dd>
<dt><b>REQUIRED TK VERSION</b></dt>
<dd>8.4 or higher on X11 and Mac OS X/11+; 8.6b2 or later on Windows.</dd>
<dt class="tm"><b>DESCRIPTION</b></dt>
<dd>Returns the path name of the "focus check window" associated with the
<code><i>widget</i></code> argument. This is the window that is used
in the binding scripts for the tag <code><b><a href=
"#adapt">WheeleventRedir</a></b></code> instead of the widget when checking
whether the focus is on/inside or outside that window. If the command
<code><b><a href=
"#setFocusCkWin">scrollutil::setFocusCheckWindow</a></b></code> was not
invoked for <code><i>widget</i></code> then the return value is
<code><i>widget</i></code> itself.</dd>
<dt class="tm"><b>KEYWORDS</b></dt>
<dd>binding, focus, "focus check window"</dd>
</dl>
<div>
<p><a href="#contents">Contents</a> <a href=
"index.html">Start page</a></p>
</div>
<hr>
</body>
</html>
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