LibWeb: Add a hook for when an URL is dropped on an HtmlView

Embedders of HtmlView can now react to this by hooking on_url_drop.

Libraries/LibWeb/HtmlView.cpp

@@ -27,6 +27,7 @@
 #include <AK/FileSystemPath.h>
 #include <AK/URL.h>
 #include <LibCore/File.h>
+#include <LibCore/MimeData.h>
 #include <LibGUI/Application.h>
 #include <LibGUI/Painter.h>
 #include <LibGUI/ScrollBar.h>
@@ -590,4 +591,15 @@ void HtmlView::run_javascript_url(const String& url)
     document()->run_javascript(source);
 }
 
+void HtmlView::drop_event(GUI::DropEvent& event)
+{
+    if (event.mime_data().has_urls()) {
+        if (on_url_drop) {
+            on_url_drop(event.mime_data().urls().first());
+            return;
+        }
+    }
+    ScrollableWidget::drop_event(event);
+}
+
 }

Libraries/LibWeb/HtmlView.h

@@ -64,6 +64,7 @@ public:
     Function<void(const String&)> on_title_change;
     Function<void(const URL&)> on_load_start;
     Function<void(const Gfx::Bitmap&)> on_favicon_change;
+    Function<void(const URL&)> on_url_drop;
 
     virtual bool accepts_focus() const override { return true; }
 
@@ -76,6 +77,7 @@ protected:
     virtual void mousedown_event(GUI::MouseEvent&) override;
     virtual void mouseup_event(GUI::MouseEvent&) override;
     virtual void keydown_event(GUI::KeyEvent&) override;
+    virtual void drop_event(GUI::DropEvent&) override;
 
 private:
     virtual void did_scroll() override;