wayland: fix screen rotation issue on Wayland (#411)

Signed-off-by: Makoto Sato <[email protected]>

Author: makotosato-at

src/flutter/shell/platform/linux_embedded/window/elinux_window_wayland.cc

@@ -628,6 +628,8 @@ const wl_output_listener ELinuxWindowWayland::kWlOutputListener = {
                    const char* model,
                    int32_t output_transform) -> void {
       ELINUX_LOG(TRACE) << "wl_output_listener.geometry";
+      auto self = reinterpret_cast<ELinuxWindowWayland*>(data);
+      self->transform_ = output_transform;
     },
     .mode = [](void* data,
                wl_output* wl_output,
@@ -639,7 +641,11 @@ const wl_output_listener ELinuxWindowWayland::kWlOutputListener = {
 
       auto self = reinterpret_cast<ELinuxWindowWayland*>(data);
       if (flags & WL_OUTPUT_MODE_CURRENT) {
-        if (self->current_rotation_ == 90 || self->current_rotation_ == 270) {
+        if (self->current_rotation_ == 90 || self->current_rotation_ == 270 ||
+            self->transform_ == WL_OUTPUT_TRANSFORM_90 ||
+            self->transform_ == WL_OUTPUT_TRANSFORM_270 ||
+            self->transform_ == WL_OUTPUT_TRANSFORM_FLIPPED_90 ||
+            self->transform_ == WL_OUTPUT_TRANSFORM_FLIPPED_270) {
           std::swap(width, height);
         }
 

src/flutter/shell/platform/linux_embedded/window/elinux_window_wayland.h

@@ -153,6 +153,7 @@ class ELinuxWindowWayland : public ELinuxWindow, public WindowBindingHandler {
   bool maximised_;
   uint32_t last_frame_time_;
   bool enable_impeller_ = false;
+  int32_t transform_ = WL_OUTPUT_TRANSFORM_NORMAL;
 
   // Indicates that exists a keyboard show request from Flutter Engine.
   bool is_requested_show_virtual_keyboard_;