Horizontal scrolling of nested ScrolledWindows in PanelPaned lags
UI file:
<?xml version="1.0" encoding="UTF-8"?>
<interface>
<requires lib="gtk" version="4.0"/>
<requires lib="Adw" version="1.0"/>
<requires lib="Panel" version="1.0"/>
<template class="ExampleWindow" parent="AdwApplicationWindow">
<property name="title">Panel Example</property>
<property name="default-width">900</property>
<property name="default-height">600</property>
<style>
<class name="devel"/>
</style>
<child>
<object class="GtkScrolledWindow">
<child>
<object class="PanelPaned">
<child>
<object class="GtkScrolledWindow">
<property name="hscrollbar-policy">never</property>
<child>
<object id="button1" class="GtkButton">
<property name="label">Button 1</property>
</object>
</child>
</object>
</child>
<child>
<object class="GtkScrolledWindow">
<property name="hscrollbar-policy">never</property>
<child>
<object id="button2" class="GtkButton">
<property name="label">Button 1</property>
</object>
</child>
</object>
</child>
<child>
<object class="GtkScrolledWindow">
<property name="hscrollbar-policy">never</property>
<child>
<object id="button3" class="GtkButton">
<property name="label">Button 1</property>
</object>
</child>
</object>
</child>
<child>
<object class="GtkScrolledWindow">
<property name="hscrollbar-policy">never</property>
<child>
<object id="button4" class="GtkButton">
<property name="label">Button 1</property>
</object>
</child>
</object>
</child>
<child>
<object class="GtkScrolledWindow">
<property name="hscrollbar-policy">never</property>
<child>
<object id="button5" class="GtkButton">
<property name="label">Button 1</property>
</object>
</child>
</object>
</child>
</object>
</child>
</object>
</child>
</template>
</interface>
On my laptop, if you make the window small enough to cause a horizontal scrollbar to be needed, two-finger scrolling horizontally won't start until you take your fingers off the touchpad. I would expect the scrolling to start immediately. If you start scrolling while moused over a divider, scrolling works as expected.
Edited by Andy Russell