Do not default window size (#3623)

Stop pretending (mostly) that windows we don't know the size of are
640x480, 100x100, or 1x1.

src/miral/basic_window_manager.cpp

@@ -1855,10 +1855,7 @@ auto miral::BasicWindowManager::place_new_surface(WindowSpecification parameters
     if (!parameters.state().is_set())
         parameters.state() = mir_window_state_restored;
 
-    if (!parameters.size().is_set())
-    {
-        parameters.size() = {640, 480};
-    }
+    auto const proposed_size = parameters.size().value_or({640, 480});
 
     std::shared_ptr<DisplayArea> display_area;
     if (parameters.output_id().is_set())
@@ -1890,7 +1887,7 @@ auto miral::BasicWindowManager::place_new_surface(WindowSpecification parameters
             auto const position = place_relative(
                 parent_content_area,
                 parameters,
-                parameters.size().value());
+                proposed_size);
 
             if (position.is_set())
             {
@@ -1911,8 +1908,8 @@ auto miral::BasicWindowManager::place_new_surface(WindowSpecification parameters
             auto const parent = info_for(parameters.parent().value()).window();
             auto const parent_top_left = parent.top_left();
             auto const centred = parent_top_left
-                                 + 0.5*(as_displacement(parent.size()) - as_displacement(parameters.size().value()))
-                                 - (as_delta(parent.size().height) - as_delta(parameters.size().value().height)) / 6;
+                                 + 0.5*(as_displacement(parent.size()) - as_displacement(proposed_size))
+                                 - (as_delta(parent.size().height) - as_delta(proposed_size.height)) / 6;
 
             parameters.top_left() = centred;
             positioned = true;
@@ -1932,8 +1929,8 @@ auto miral::BasicWindowManager::place_new_surface(WindowSpecification parameters
     if (!positioned)
     {
         auto centred = application_zone.top_left
-                       + 0.5*(as_displacement(application_zone.size) - as_displacement(parameters.size().value()))
-                       - (as_delta(application_zone.size.height) - as_delta(parameters.size().value().height)) / 6;
+                       + 0.5*(as_displacement(application_zone.size) - as_displacement(proposed_size))
+                       - (as_delta(application_zone.size.height) - as_delta(proposed_size.height)) / 6;
 
         switch (parameters.state().value())
         {
@@ -1950,13 +1947,13 @@ auto miral::BasicWindowManager::place_new_surface(WindowSpecification parameters
         case mir_window_state_vertmaximized:
             centred.y = application_zone.top_left.y;
             parameters.top_left() = centred;
-            parameters.size() = Size{parameters.size().value().width, application_zone.size.height};
+            parameters.size() = Size{proposed_size.width, application_zone.size.height};
             break;
 
         case mir_window_state_horizmaximized:
             centred.x = application_zone.top_left.x;
             parameters.top_left() = centred;
-            parameters.size() = Size{application_zone.size.width, parameters.size().value().height};
+            parameters.size() = Size{application_zone.size.width, proposed_size.height};
             break;
 
         default:

src/server/frontend_wayland/window_wl_surface_role.cpp

@@ -294,22 +294,16 @@ auto mf::WindowWlSurfaceRole::pending_size() const -> geom::Size
 
 auto mf::WindowWlSurfaceRole::current_size() const -> geom::Size
 {
-    auto size = geom::Size{640, 480};
-    if ((!committed_width_set_explicitly || !committed_height_set_explicitly) && surface)
+    if (surface)
     {
-        if (auto const buffer_size = surface.value().buffer_size())
-        {
-            if (!committed_width_set_explicitly)
-            {
-                size.width = buffer_size->width;
-            }
-            if (!committed_height_set_explicitly)
-            {
-                size.height = buffer_size->height;
-            }
-        }
+        auto const buffer_size = surface.value().buffer_size().value_or(geom::Size{});
+
+        return {
+            committed_width_set_explicitly.value_or(buffer_size.width),
+            committed_height_set_explicitly.value_or(buffer_size.height)};
     }
-    return size;
+
+    return geom::Size{0, 0};
 }
 
 auto mf::WindowWlSurfaceRole::requested_window_size() const -> std::optional<geom::Size>
@@ -389,9 +383,9 @@ void mf::WindowWlSurfaceRole::commit(WlSurfaceState const& state)
     }
 
     if (pending_explicit_width)
-        committed_width_set_explicitly = true;
+        committed_width_set_explicitly = pending_explicit_width;
     if (pending_explicit_height)
-        committed_height_set_explicitly = true;
+        committed_height_set_explicitly = pending_explicit_height;
     pending_explicit_width = std::nullopt;
     pending_explicit_height = std::nullopt;
 

src/server/frontend_wayland/window_wl_surface_role.h

@@ -155,8 +155,8 @@ class WindowWlSurfaceRole
 
     /// If the committed window size was set explicitly, rather than being taken from the buffer size
     /// @{
-    bool committed_width_set_explicitly{false};
-    bool committed_height_set_explicitly{false};
+    std::optional<geometry::Width> committed_width_set_explicitly;
+    std::optional<geometry::Height> committed_height_set_explicitly;
     /// @}
 
     /// The min and max size of the window as of last commit

src/server/scene/basic_surface.cpp

@@ -982,8 +982,8 @@ void mir::scene::BasicSurface::update_frame_posted_callbacks(State& state)
 auto mir::scene::BasicSurface::content_size(State const& state) const -> geometry::Size
 {
     return geom::Size{
-        std::max(state.surface_rect.size.width - state.margins.left - state.margins.right, geom::Width{1}),
-        std::max(state.surface_rect.size.height - state.margins.top - state.margins.bottom, geom::Height{1})};
+        std::max(state.surface_rect.size.width - state.margins.left - state.margins.right, geom::Width{0}),
+        std::max(state.surface_rect.size.height - state.margins.top - state.margins.bottom, geom::Height{0})};
 }
 
 auto mir::scene::BasicSurface::content_top_left(State const& state) const -> geometry::Point

src/server/scene/surface_allocator.cpp

@@ -44,9 +44,8 @@ std::shared_ptr<ms::Surface> ms::SurfaceAllocator::create_surface(
     auto confine = params.confine_pointer.is_set() ? params.confine_pointer.value() : mir_pointer_unconfined;
     auto const name = params.name.is_set() ? params.name.value() : "";
     geom::Rectangle const rect{
-        params.top_left.is_set() ? params.top_left.value() : geom::Point{}, {
-            params.width.is_set() ? params.width.value() : geom::Width{100},
-            params.height.is_set() ? params.height.value() : geom::Height{100}}};
+        params.top_left.value_or(geom::Point{}),
+        {params.width.value_or(geom::Width{0}), params.height.value_or(geom::Height{0})}};
     auto const parent = params.parent.is_set() ? params.parent.value() : std::weak_ptr<scene::Surface>{};
     auto const surface = std::make_shared<BasicSurface>(
         session,