From aedc9e62e611c06a3e01d50b8f5bdf8e19e52582 Mon Sep 17 00:00:00 2001
From: David Edmundson <kde@davidedmundson.co.uk>
Date: Thu, 14 Nov 2019 12:50:45 +0000
Subject: [PATCH] [effects] Forward wheel events

Summary:
Effects::checkInputWindowEvent(QWheelEvent *e) existed but it was not
hooked up to anything and would never be called.

This patch adds the relevant handling in the wayland filter, X filter so
the existing method gets called.

EffectQuickView is updated to handle wheel events.

Test Plan:
Used a ListView via an EffectQuickView in an effect.
I can now scroll with the mouse.

Reviewers: #kwin, zzag

Reviewed By: #kwin, zzag

Subscribers: zzag, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D25292
---
 input.cpp                                     |  6 ++++
 libkwineffects/kwineffectquickview.cpp        | 10 ++++++
 .../effects_mouse_interception_x11_filter.cpp | 36 +++++++++++++++++++
 3 files changed, 52 insertions(+)

diff --git a/input.cpp b/input.cpp
index 8f57a1e57b..2b21c3b60f 100644
--- a/input.cpp
+++ b/input.cpp
@@ -411,6 +411,12 @@ public:
         }
         return static_cast<EffectsHandlerImpl*>(effects)->checkInputWindowEvent(event);
     }
+    bool wheelEvent(QWheelEvent *event) override {
+        if (!effects) {
+            return false;
+        }
+        return static_cast<EffectsHandlerImpl*>(effects)->checkInputWindowEvent(event);
+    }
     bool keyEvent(QKeyEvent *event) override {
         if (!effects || !static_cast< EffectsHandlerImpl* >(effects)->hasKeyboardGrab()) {
             return false;
diff --git a/libkwineffects/kwineffectquickview.cpp b/libkwineffects/kwineffectquickview.cpp
index 9b61a1e0d0..b57d69e102 100644
--- a/libkwineffects/kwineffectquickview.cpp
+++ b/libkwineffects/kwineffectquickview.cpp
@@ -226,6 +226,16 @@ void EffectQuickView::forwardMouseEvent(QEvent *e)
         e->setAccepted(cloneEvent.isAccepted());
         return;
     }
+    case QEvent::Wheel:
+    {
+        QWheelEvent *we = static_cast<QWheelEvent *>(e);
+        const QPointF widgetPos = d->m_view->mapFromGlobal(we->pos());
+        QWheelEvent cloneEvent(widgetPos, we->globalPosF(), we->pixelDelta(), we->angleDelta(), we->buttons(),
+                               we->modifiers(), we->phase(), we->inverted());
+        QCoreApplication::sendEvent(d->m_view, &cloneEvent);
+        e->setAccepted(cloneEvent.isAccepted());
+        return;
+    }
     default:
         return;
     }
diff --git a/plugins/platforms/x11/standalone/effects_mouse_interception_x11_filter.cpp b/plugins/platforms/x11/standalone/effects_mouse_interception_x11_filter.cpp
index e33dedbaae..ffa38530fa 100644
--- a/plugins/platforms/x11/standalone/effects_mouse_interception_x11_filter.cpp
+++ b/plugins/platforms/x11/standalone/effects_mouse_interception_x11_filter.cpp
@@ -39,6 +39,42 @@ bool EffectsMouseInterceptionX11Filter::event(xcb_generic_event_t *event)
     if (eventType == XCB_BUTTON_PRESS || eventType == XCB_BUTTON_RELEASE) {
         auto *me = reinterpret_cast<xcb_button_press_event_t*>(event);
         if (m_window == me->event) {
+            const bool isWheel = me->detail >= 4 || me->detail <= 7;
+            if (isWheel) {
+                if (eventType != XCB_BUTTON_PRESS) {
+                    return false;
+                }
+                QPoint angleDelta;
+                switch (me->detail) {
+                case 4:
+                    angleDelta.setY(120);
+                    break;
+                case 5:
+                    angleDelta.setY(-120);
+                    break;
+                case 6:
+                    angleDelta.setX(120);
+                    break;
+                case 7:
+                    angleDelta.setX(-120);
+                    break;
+                }
+
+                const Qt::MouseButtons buttons = x11ToQtMouseButtons(me->state);
+                const Qt::KeyboardModifiers modifiers = x11ToQtKeyboardModifiers(me->state);
+
+                if (modifiers & Qt::AltModifier) {
+                    angleDelta = angleDelta.transposed();
+                }
+
+                if (angleDelta.y()) {
+                    QWheelEvent ev(QPoint(me->event_x, me->event_y), angleDelta.y(), buttons, modifiers, Qt::Vertical);
+                    return m_effects->checkInputWindowEvent(&ev);
+                } else if (angleDelta.x()) {
+                    QWheelEvent ev(QPoint(me->event_x, me->event_y), angleDelta.x(), buttons, modifiers, Qt::Horizontal);
+                    return m_effects->checkInputWindowEvent(&ev);
+                }
+            }
             const Qt::MouseButton button = x11ToQtMouseButton(me->detail);
             Qt::MouseButtons buttons = x11ToQtMouseButtons(me->state);
             const QEvent::Type type = (eventType == XCB_BUTTON_PRESS) ? QEvent::MouseButtonPress : QEvent::MouseButtonRelease;