Decoration strategy

src/server/shell/abstract_shell.cpp

@@ -16,7 +16,6 @@
 
 #include "mir/shell/abstract_shell.h"
 
-#include "mir/shell/decoration.h"
 #include "mir/shell/input_targeter.h"
 #include "mir/shell/shell_report.h"
 #include "mir/shell/surface_specification.h"
@@ -233,7 +232,7 @@ auto msh::AbstractShell::create_surface(
     if (wm_visible_spec.server_side_decorated.value_or(false) && wm_visible_spec.width.is_set() && wm_visible_spec.height.is_set())
     {
         geom::Size const content_size{wm_visible_spec.width.value(), wm_visible_spec.height.value()};
-        auto const size = decoration::compute_size_with_decorations(
+        auto const size = decoration_manager->compute_size_with_decorations(
             content_size,
             wm_visible_spec.type.value(),
             wm_visible_spec.state.value());
@@ -302,7 +301,7 @@ void msh::AbstractShell::modify_surface(std::shared_ptr<scene::Session> const& s
             wm_relevant_mods.height = content_size.height;
 
             // When adding decorations we need to resize the window for WM
-            window_size = decoration::compute_size_with_decorations(
+            window_size = decoration_manager->compute_size_with_decorations(
                 content_size,
                 modifications.type.value_or(surface->type()),
                 modifications.state.value_or(surface->state()));

src/server/shell/decoration/CMakeLists.txt

@@ -9,7 +9,8 @@ set(
   basic_decoration.h    basic_decoration.cpp
   window.h              window.cpp
   input.h               input.cpp
-  renderer.h            renderer.cpp renderer_default.cpp
+  renderer.h            renderer.cpp
+  decoration_strategy.h decoration_strategy.cpp
 )
 
 add_library(

src/server/shell/decoration/basic_decoration.cpp

@@ -42,23 +42,6 @@ namespace geom = mir::geometry;
 namespace msh = mir::shell;
 namespace msd = mir::shell::decoration;
 
-namespace mir::shell::decoration
-{
-// See src/server/shell/decoration/window.h for a full description of each property
-StaticGeometry const default_geometry {
-    geom::Height{24},   // titlebar_height
-    geom::Width{6},     // side_border_width
-    geom::Height{6},    // bottom_border_height
-    geom::Size{16, 16}, // resize_corner_input_size
-    geom::Width{24},    // button_width
-    geom::Width{6},     // padding_between_buttons
-    geom::Height{14},   // title_font_height
-    geom::Point{8, 2},  // title_font_top_left
-    geom::Displacement{5, 5}, // icon_padding
-    geom::Width{1},     // detail_line_width
-};
-}
-
 namespace
 {
 template<typename OBJ>
@@ -146,37 +129,30 @@ msd::BasicDecoration::BufferStreams::~BufferStreams()
     session->destroy_buffer_stream(bottom_border);
 }
 
-auto msd::BasicDecoration::BufferStreams::create_buffer_stream() -> std::shared_ptr<mc::BufferStream>
-{
-    auto const stream = session->create_buffer_stream(mg::BufferProperties{
-        geom::Size{1, 1},
-        buffer_format,
-        mg::BufferUsage::software});
-    return stream;
-}
-
 msd::BasicDecoration::BasicDecoration(
     std::shared_ptr<msh::Shell> const& shell,
     std::shared_ptr<mg::GraphicBufferAllocator> const& buffer_allocator,
     std::shared_ptr<Executor> const& executor,
     std::shared_ptr<input::CursorImages> const& cursor_images,
-    std::shared_ptr<ms::Surface> const& window_surface)
+    std::shared_ptr<ms::Surface> const& window_surface,
+    std::shared_ptr<DecorationStrategy> decoration_strategy)
     : threadsafe_self{std::make_shared<ThreadsafeAccess<BasicDecoration>>(executor)},
-      static_geometry{std::make_shared<StaticGeometry>(default_geometry)},
+      decoration_strategy{decoration_strategy},
+      static_geometry{decoration_strategy->static_geometry()},
       shell{shell},
       buffer_allocator{buffer_allocator},
       cursor_images{cursor_images},
       session{window_surface->session().lock()},
       buffer_streams{std::make_unique<BufferStreams>(session, static_geometry->buffer_format)},
-      renderer{std::make_unique<Renderer>(buffer_allocator, RendererStrategy::default_strategy(static_geometry))},
+      renderer{std::make_unique<Renderer>(buffer_allocator, decoration_strategy->render_strategy())},
       window_surface{window_surface},
       decoration_surface{create_surface()},
       window_state{new_window_state()},
       window_surface_observer_manager{std::make_unique<WindowSurfaceObserverManager>(
           window_surface,
           threadsafe_self)},
       input_manager{std::make_unique<InputManager>(
-          static_geometry,
+          decoration_strategy,
           decoration_surface,
           *window_state,
           threadsafe_self)},
@@ -194,6 +170,15 @@ msd::BasicDecoration::BasicDecoration(
     threadsafe_self->initialize(this);
 }
 
+auto msd::BasicDecoration::BufferStreams::create_buffer_stream() -> std::shared_ptr<mc::BufferStream>
+{
+    auto const stream = session->create_buffer_stream(mg::BufferProperties{
+        geom::Size{1, 1},
+        buffer_format,
+        mg::BufferUsage::software});
+    return stream;
+}
+
 msd::BasicDecoration::~BasicDecoration()
 {
     threadsafe_self->invalidate();

src/server/shell/decoration/basic_decoration.h

@@ -18,6 +18,7 @@
 #define MIR_SHELL_DECORATION_BASIC_DECORATION_H_
 
 #include "decoration.h"
+#include "decoration_strategy.h"
 
 #include "mir/geometry/rectangle.h"
 #include "mir_toolkit/common.h"
@@ -72,7 +73,8 @@ class BasicDecoration
         std::shared_ptr<graphics::GraphicBufferAllocator> const& buffer_allocator,
         std::shared_ptr<Executor> const& executor,
         std::shared_ptr<input::CursorImages> const& cursor_images,
-        std::shared_ptr<scene::Surface> const& window_surface);
+        std::shared_ptr<scene::Surface> const& window_surface,
+        std::shared_ptr<DecorationStrategy> decoration_strategy);
     ~BasicDecoration();
 
     void window_state_updated();
@@ -103,7 +105,8 @@ class BasicDecoration
         std::optional<InputState const*> previous_input_state);
 
     std::shared_ptr<ThreadsafeAccess<BasicDecoration>> const threadsafe_self;
-    std::shared_ptr<StaticGeometry const> const static_geometry;
+    std::shared_ptr<DecorationStrategy> const decoration_strategy;
+    std::shared_ptr<StaticGeometry> const static_geometry;
 
     std::shared_ptr<shell::Shell> const shell;
     std::shared_ptr<graphics::GraphicBufferAllocator> const buffer_allocator;

src/server/shell/decoration/basic_manager.cpp

@@ -16,6 +16,7 @@
 
 #include "basic_manager.h"
 #include "decoration.h"
+#include "decoration_strategy.h"
 
 #include <mir/graphics/display_configuration.h>
 #include <mir/graphics/null_display_configuration_observer.h>
@@ -49,8 +50,10 @@ class msd::DisplayConfigurationListener :  public mg::NullDisplayConfigurationOb
 };
 
 msd::BasicManager::BasicManager(
+    std::shared_ptr<DecorationStrategy> const& decoration_strategy,
     ObserverRegistrar<mg::DisplayConfigurationObserver>& display_configuration_observers,
     DecorationBuilder&& decoration_builder) :
+    decoration_strategy{decoration_strategy},
     decoration_builder{std::move(decoration_builder)},
     display_config_monitor{std::make_shared<DisplayConfigurationListener>(
         [&](mg::DisplayConfiguration const& config)
@@ -92,7 +95,7 @@ void msd::BasicManager::decorate(std::shared_ptr<ms::Surface> const& surface)
     {
         decorations[surface.get()] = nullptr;
         lock.unlock();
-        auto decoration = decoration_builder(locked_shell, surface);
+        auto decoration = decoration_builder(decoration_strategy, locked_shell, surface);
         lock.lock();
         decoration->set_scale(scale);
         decorations[surface.get()] = std::move(decoration);
@@ -128,6 +131,29 @@ void msd::BasicManager::undecorate_all()
     to_destroy.clear();
 }
 
+using mir::geometry::Size;
+
+auto msd::BasicManager::compute_size_with_decorations(Size content_size,
+    MirWindowType type, MirWindowState state) -> Size
+{
+    auto const geometry = decoration_strategy->static_geometry();
+
+    switch (border_type_for(type, state))
+    {
+    case msd::BorderType::Full:
+        content_size.width += geometry->side_border_width * 2;
+        content_size.height += geometry->titlebar_height + geometry->bottom_border_height;
+        break;
+    case msd::BorderType::Titlebar:
+        content_size.height += geometry->titlebar_height;
+        break;
+    case msd::BorderType::None:
+        break;
+    }
+
+    return content_size;
+}
+
 void msd::BasicManager::set_scale(float new_scale)
 {
     std::lock_guard lock{mutex};
@@ -139,4 +165,4 @@ void msd::BasicManager::set_scale(float new_scale)
             it.second->set_scale(scale);
         }
     }
-}
+}

src/server/shell/decoration/basic_manager.h

@@ -40,6 +40,7 @@ class Shell;
 namespace decoration
 {
 class Decoration;
+class DecorationStrategy;
 class DisplayConfigurationListener;
 
 /// Facilitates decorating windows with Mir's built-in server size decorations
@@ -48,10 +49,12 @@ class BasicManager :
 {
 public:
     using DecorationBuilder = std::function<std::unique_ptr<Decoration>(
+        std::shared_ptr<DecorationStrategy> const& decoration_strategy,
         std::shared_ptr<shell::Shell> const& shell,
         std::shared_ptr<scene::Surface> const& surface)>;
 
     BasicManager(
+        std::shared_ptr<DecorationStrategy> const& decoration_strategy,
         mir::ObserverRegistrar<mir::graphics::DisplayConfigurationObserver>& display_configuration_observers,
         DecorationBuilder&& decoration_builder);
     ~BasicManager();
@@ -60,8 +63,11 @@ class BasicManager :
     void decorate(std::shared_ptr<scene::Surface> const& surface) override;
     void undecorate(std::shared_ptr<scene::Surface> const& surface) override;
     void undecorate_all() override;
+    auto compute_size_with_decorations(geometry::Size content_size, MirWindowType type,
+        MirWindowState state) -> geometry::Size override;
 
 private:
+    std::shared_ptr<DecorationStrategy> const decoration_strategy;
     DecorationBuilder const decoration_builder;
     std::shared_ptr<DisplayConfigurationListener> const display_config_monitor;
     std::weak_ptr<shell::Shell> shell;