CAN HAZ SKROL INVERZUN? Can haz.

Author: japhb

docs/preferences.md

@@ -83,8 +83,14 @@ currently recognized by Terminal::Widgets:
 * `Bool input-activation-flash` - If `True`, flash Input widgets when
   activated, such as when a Button is clicked.  Defaults to `False`.
 
+* `UInt mouse-wheel-horizontal-speed` - Sets number of scrolled cells per mouse
+  wheel horizontal event, defaulting to twice `mouse-wheel-vertical-speed`.
+
 * `UInt mouse-wheel-vertical-speed` - Sets number of scrolled lines per mouse
   wheel vertical event, defaulting to 4 lines per event.
 
-* `UInt mouse-wheel-horizontal-speed` - Sets number of scrolled cells per mouse
-  wheel horizontal event, defaulting to twice `mouse-wheel-vertical-speed`.
+* `Bool scroll-invert-horizontal` - If `True`, invert the direction of
+  horizontal scroll events.  Defaults to `False`.
+
+* `Bool scroll-invert-vertical` - If `True`, invert the direction of vertical
+  scroll events.  Defaults to `False`.

lib/Terminal/Widgets/ScrollBar.rakumod

@@ -63,13 +63,18 @@ class Terminal::Widgets::HScrollBar
  does Terminal::Widgets::Scrollbar {
     method h-arrow-scroll-inc() {
         my $ui-prefs = self.terminal.ui-prefs;
+        my $h-invert = $ui-prefs<scroll-invert-horizontal> ?? -1 !! +1;
+        my $h-speed  =         $ui-prefs<mouse-wheel-horizontal-speed>
+                       || 2 * ($ui-prefs<mouse-wheel-vertical-speed> || 4);
 
-                $ui-prefs<mouse-wheel-horizontal-speed>
-        || 2 * ($ui-prefs<mouse-wheel-vertical-speed> || 4)
+        $h-speed * $h-invert
     }
 
     method h-bar-scroll-inc() {
-        $.scroll-target.content-width
+        my $ui-prefs = self.terminal.ui-prefs;
+        my $h-invert = $ui-prefs<scroll-invert-horizontal> ?? -1 !! +1;
+
+        $.scroll-target.content-width * $h-invert
     }
 
     method arrow-left-scroll() {
@@ -235,11 +240,18 @@ class Terminal::Widgets::VScrollBar
    is Terminal::Widgets::Widget
  does Terminal::Widgets::Scrollbar {
     method v-arrow-scroll-inc() {
-        self.terminal.ui-prefs<mouse-wheel-vertical-speed> || 4
+        my $ui-prefs = self.terminal.ui-prefs;
+        my $v-invert = $ui-prefs<scroll-invert-vertical> ?? -1 !! +1;
+        my $v-speed  = $ui-prefs<mouse-wheel-vertical-speed> || 4;
+
+        $v-speed * $v-invert
     }
 
     method v-bar-scroll-inc() {
-        $.scroll-target.content-height
+        my $ui-prefs = self.terminal.ui-prefs;
+        my $v-invert = $ui-prefs<scroll-invert-vertical> ?? -1 !! +1;
+
+        $.scroll-target.content-height * $v-invert
     }
 
     method arrow-up-scroll() {

lib/Terminal/Widgets/Scrollable.rakumod

@@ -101,13 +101,15 @@ role Terminal::Widgets::Scrollable {
         my $ui-prefs = self.terminal.ui-prefs;
         my $v-speed  = $ui-prefs<mouse-wheel-vertical-speed>   || 4;
         my $h-speed  = $ui-prefs<mouse-wheel-horizontal-speed> || 2 * $v-speed;
+        my $v-invert = $ui-prefs<scroll-invert-vertical>   ?? -1 !! +1;
+        my $h-invert = $ui-prefs<scroll-invert-horizontal> ?? -1 !! +1;
 
         # Process wheel up/down/left/right
         given $event.mouse.button {
-            when 4 { self.change-y-scroll: -$v-speed }
-            when 5 { self.change-y-scroll: +$v-speed }
-            when 6 { self.change-x-scroll: -$h-speed }
-            when 7 { self.change-x-scroll: +$h-speed }
+            when 4 { self.change-y-scroll: -$v-speed * $v-invert }
+            when 5 { self.change-y-scroll: +$v-speed * $v-invert }
+            when 6 { self.change-x-scroll: -$h-speed * $h-invert }
+            when 7 { self.change-x-scroll: +$h-speed * $h-invert }
         }
 
         self.refresh-for-scroll;