Start refactoring the windowing system to use an event loop.

Userspace programs can now open /dev/gui_events and read a stream of GUI_Event
structs one at a time.

I was stuck on a stupid problem where we'd reenter Scheduler::yield() due to
having one of the has_data_available_for_reading() implementations using locks.

1 files changed, 14 insertions, 0 deletions

diff --git a/Widgets/GUIEventDevice.h b/Widgets/GUIEventDevice.h
new file mode 100644
index 0000000000..061fc96e71
--- /dev/null
+++ b/Widgets/GUIEventDevice.h
@@ -0,0 +1,14 @@
+#pragma once
+
+#include <VirtualFileSystem/CharacterDevice.h>
+
+class GUIEventDevice final : public CharacterDevice {
+public:
+    GUIEventDevice();
+    virtual ~GUIEventDevice() override;
+
+private:
+    virtual bool has_data_available_for_reading(Process&) const override;
+    virtual ssize_t read(byte* buffer, size_t bufferSize) override;
+    virtual ssize_t write(const byte* buffer, size_t bufferSize) override;
+};