[PATCH] WPrefs: add mouse wheel action to the expert panel

[david.m...@gmail.com]

This patch is adding the mouse wheel action to be performed
on the expert text frame panel.
---
 WINGs/WINGs/WINGs.h |   2 +
 WPrefs.app/Expert.c | 130 +++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 130 insertions(+), 2 deletions(-)

diff --git a/WINGs/WINGs/WINGs.h b/WINGs/WINGs/WINGs.h
index f8bb53f1..5ead0a8f 100644
--- a/WINGs/WINGs/WINGs.h
+++ b/WINGs/WINGs/WINGs.h
@@ -1533,6 +1533,8 @@ void WMSetScrollViewRelief(WMScrollView *sPtr, WMReliefType type);
 
 WMRect WMGetScrollViewVisibleRect(WMScrollView *sPtr);
 
+void WMScrollViewScrollPoint(WMScrollView * sPtr, WMPoint point);
+
 WMScroller* WMGetScrollViewHorizontalScroller(WMScrollView *sPtr);
 
 WMScroller* WMGetScrollViewVerticalScroller(WMScrollView *sPtr);
diff --git a/WPrefs.app/Expert.c b/WPrefs.app/Expert.c
index 6ef6307d..d2d33028 100644
--- a/WPrefs.app/Expert.c
+++ b/WPrefs.app/Expert.c
@@ -4,7 +4,7 @@
  *
  *  Copyright (c) 2014-2023 Window Maker Team
  *  Copyright (c) 1998-2003 Alfredo K. Kojima
- *  Copyright (c) 2009-2023 Window Maker Team
+ *  Copyright (c) 2009-2026 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -147,6 +147,8 @@ typedef struct _Panel {
  WMButton *swi[wlengthof_nocheck(expert_options)];
 
  WMTextField *textfield[wlengthof_nocheck(expert_options)];
+ WMScrollView *sv;
+ WMWidget *frame;
 
 } _Panel;
 
@@ -167,6 +169,124 @@ static void changeIntTextfield(void *data, int delta)
  WMSetTextFieldText(textfield, buffer);
 }
 
+static void scrollViewWheelHandler(XEvent *event, void *data)
+{
+ _Panel *panel = (_Panel *) data;
+ int amount, viewH, contentH, newY, maxY;
+ WMRect rect;
+ WMPoint pt;
+
+ if (!panel || !panel->sv || !panel->frame)
+ return;
+
+ if (event->type != ButtonPress)
+ return;
+
+ if (event->xbutton.button != WINGsConfiguration.mouseWheelUp &&
+ event->xbutton.button != WINGsConfiguration.mouseWheelDown)
+ return;
+
+ rect = WMGetScrollViewVisibleRect(panel->sv);
+ viewH = rect.size.height;
+ contentH = WMWidgetHeight(panel->frame);
+
+ if (event->xbutton.state & ControlMask) {
+ amount = viewH; /* page */
+ } else if (event->xbutton.state & ShiftMask) {
+ amount = 1; /* line */
+ } else {
+ amount = viewH / 3; /* default */
+ if (amount == 0)
+ amount = 1;
+ }
+
+ if (event->xbutton.button == WINGsConfiguration.mouseWheelUp)
+ amount = -amount;
+
+ newY = rect.pos.y + amount;
+ maxY = contentH - viewH;
+ if (maxY < 0)
+ maxY = 0;
+ if (newY < 0)
+ newY = 0;
+ if (newY > maxY)
+ newY = maxY;
+
+ pt.x = rect.pos.x;
+ pt.y = newY;
+
+ WMScrollViewScrollPoint(panel->sv, pt);
+}
+
+static void scrollViewRealizeObserver(void *self, WMNotification *not)
+{
+ (void) not;
+ _Panel *panel = (_Panel *) self;
+ Display *dpy = NULL;
+ Window viewport_win = 0;
+ WMView *frameView;
+
+ if (!panel || !panel->frame)
+ return;
+
+ frameView = WMWidgetView(panel->frame);
+
+ if (frameView && frameView->parent) {
+ dpy = frameView->screen->display;
+ viewport_win = frameView->parent->window;
+ }
+
+ /* fallback: use the scrollview's view window if parent viewport not available */
+ if (!viewport_win && panel->sv) {
+ WMView *svView = WMWidgetView(panel->sv);
+ if (svView && svView->screen) {
+ dpy = svView->screen->display;
+ viewport_win = svView->window;
+ }
+ }
+
+ if (!dpy || viewport_win == 0)
+ return;
+
+ XGrabButton(dpy, WINGsConfiguration.mouseWheelUp, AnyModifier, viewport_win,
+ True, ButtonPressMask, GrabModeAsync, GrabModeAsync, None, None);
+ XGrabButton(dpy, WINGsConfiguration.mouseWheelDown, AnyModifier, viewport_win,
+ True, ButtonPressMask, GrabModeAsync, GrabModeAsync, None, None);
+}
+
+static void scrollViewPrepareForClose(Panel *p)
+{
+ _Panel *panel = (_Panel *) p;
+ Display *dpy = NULL;
+ Window viewport_win = 0;
+
+ if (!panel)
+ return;
+
+ if (panel->frame) {
+ WMView *frameView = WMWidgetView(panel->frame);
+ if (frameView && frameView->parent) {
+ dpy = frameView->screen->display;
+ viewport_win = frameView->parent->window;
+ }
+ }
+
+ if (!viewport_win && panel->sv) {
+ WMView *svView = WMWidgetView(panel->sv);
+ if (svView && svView->screen) {
+ dpy = svView->screen->display;
+ viewport_win = svView->window;
+ }
+ }
+
+ if (dpy && viewport_win != 0) {
+ XUngrabButton(dpy, WINGsConfiguration.mouseWheelUp, AnyModifier, viewport_win);
+ XUngrabButton(dpy, WINGsConfiguration.mouseWheelDown, AnyModifier, viewport_win);
+ }
+
+ WMRemoveNotificationObserver(panel);
+}
+
 static void downButtonCallback(WMWidget *self, void *data)
 {
  (void) self;
@@ -290,7 +410,7 @@ static void createPanel(Panel *p)
 
  default:
 #ifdef DEBUG
- wwarning("export_options[%d].class = %d, this should not happen\n",
+ wwarning("expert_options[%d].class = %d, this should not happen\n",
  i, expert_options[i].class);
 #endif
  state = expert_options[i].def_state;
@@ -302,6 +422,11 @@ static void createPanel(Panel *p)
 
  WMMapSubwidgets(panel->box);
  WMSetScrollViewContentView(sv, WMWidgetView(f));
+ /* keep references for the wheel handler and register it */
+ panel->sv = sv;
+ panel->frame = f;
+ WMCreateEventHandler(WMWidgetView(sv), ButtonPressMask, scrollViewWheelHandler, panel);
+ WMAddNotificationObserver(scrollViewRealizeObserver, panel, WMViewRealizedNotification, WMWidgetView(sv));
  WMRealizeWidget(panel->box);
 }
 
@@ -362,6 +487,7 @@ Panel *InitExpert(WMWidget *parent)
 
  panel->callbacks.createWidgets = createPanel;
  panel->callbacks.updateDomain = storeDefaults;
+ panel->callbacks.prepareForClose = scrollViewPrepareForClose;
 
  AddSection(panel, ICON_FILE);
 
--
2.43.0