LibWeb: Return whether handle_mousewheel was handled

We try scrolling a Node with the handle_mousewheel event, but if it
isn't scrollable, the event should be passed back up to the page
host. This is the first step in that process.

5 files changed, 13 insertions, 7 deletions

diff --git a/Userland/Libraries/LibWeb/Layout/BlockBox.cpp b/Userland/Libraries/LibWeb/Layout/BlockBox.cpp
index d46b743721..5a9f2b5c43 100644
--- a/Userland/Libraries/LibWeb/Layout/BlockBox.cpp
+++ b/Userland/Libraries/LibWeb/Layout/BlockBox.cpp
@@ -156,13 +156,15 @@ void BlockBox::set_scroll_offset(const Gfx::FloatPoint& offset)
     set_needs_display();
 }
 
-void BlockBox::handle_mousewheel(Badge<EventHandler>, const Gfx::IntPoint&, unsigned int, unsigned int, int wheel_delta)
+bool BlockBox::handle_mousewheel(Badge<EventHandler>, const Gfx::IntPoint&, unsigned int, unsigned int, int wheel_delta)
 {
     if (!is_scrollable())
-        return;
+        return false;
     auto new_offset = m_scroll_offset;
     new_offset.move_by(0, wheel_delta);
     set_scroll_offset(new_offset);
+
+    return true;
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/Layout/BlockBox.h b/Userland/Libraries/LibWeb/Layout/BlockBox.h
index 5d6951a0e0..269a6b939c 100644
--- a/Userland/Libraries/LibWeb/Layout/BlockBox.h
+++ b/Userland/Libraries/LibWeb/Layout/BlockBox.h
@@ -60,7 +60,7 @@ public:
 private:
     virtual bool is_block_box() const final { return true; }
     virtual bool wants_mouse_events() const override { return true; }
-    virtual void handle_mousewheel(Badge<EventHandler>, const Gfx::IntPoint&, unsigned buttons, unsigned modifiers, int wheel_delta) override;
+    virtual bool handle_mousewheel(Badge<EventHandler>, const Gfx::IntPoint&, unsigned buttons, unsigned modifiers, int wheel_delta) override;
 
     bool should_clip_overflow() const;
 
diff --git a/Userland/Libraries/LibWeb/Layout/Node.cpp b/Userland/Libraries/LibWeb/Layout/Node.cpp
index 7a72dfbca5..b2c1cd4661 100644
--- a/Userland/Libraries/LibWeb/Layout/Node.cpp
+++ b/Userland/Libraries/LibWeb/Layout/Node.cpp
@@ -322,15 +322,18 @@ void Node::handle_mousemove(Badge<EventHandler>, const Gfx::IntPoint&, unsigned,
 {
 }
 
-void Node::handle_mousewheel(Badge<EventHandler>, const Gfx::IntPoint&, unsigned, unsigned, int wheel_delta)
+bool Node::handle_mousewheel(Badge<EventHandler>, const Gfx::IntPoint&, unsigned, unsigned, int wheel_delta)
 {
     if (auto* containing_block = this->containing_block()) {
         if (!containing_block->is_scrollable())
-            return;
+            return false;
         auto new_offset = containing_block->scroll_offset();
         new_offset.move_by(0, wheel_delta);
         containing_block->set_scroll_offset(new_offset);
+        return true;
     }
+
+    return false;
 }
 
 bool Node::is_root_element() const
diff --git a/Userland/Libraries/LibWeb/Layout/Node.h b/Userland/Libraries/LibWeb/Layout/Node.h
index 653baa5264..917f9607b3 100644
--- a/Userland/Libraries/LibWeb/Layout/Node.h
+++ b/Userland/Libraries/LibWeb/Layout/Node.h
@@ -109,7 +109,7 @@ public:
     virtual void handle_mousedown(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned modifiers);
     virtual void handle_mouseup(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned modifiers);
     virtual void handle_mousemove(Badge<EventHandler>, const Gfx::IntPoint&, unsigned buttons, unsigned modifiers);
-    virtual void handle_mousewheel(Badge<EventHandler>, const Gfx::IntPoint&, unsigned buttons, unsigned modifiers, int wheel_delta);
+    virtual bool handle_mousewheel(Badge<EventHandler>, const Gfx::IntPoint&, unsigned buttons, unsigned modifiers, int wheel_delta);
 
     virtual void before_children_paint(PaintContext&, PaintPhase) {};
     virtual void paint(PaintContext&, PaintPhase);
diff --git a/Userland/Libraries/LibWeb/Page/EventHandler.cpp b/Userland/Libraries/LibWeb/Page/EventHandler.cpp
index 688dc0b9c2..f4f4cd886d 100644
--- a/Userland/Libraries/LibWeb/Page/EventHandler.cpp
+++ b/Userland/Libraries/LibWeb/Page/EventHandler.cpp
@@ -139,7 +139,8 @@ bool EventHandler::handle_mousewheel(const Gfx::IntPoint& position, unsigned int
 
     auto result = layout_root()->hit_test(position, Layout::HitTestType::Exact);
     if (result.layout_node) {
-        result.layout_node->handle_mousewheel({}, position, buttons, modifiers, wheel_delta);
+        if (result.layout_node->handle_mousewheel({}, position, buttons, modifiers, wheel_delta))
+            return true;
         return true;
     }