4 files changed, 101 insertions, 38 deletions

diff --git a/src/common/emu_window.h b/src/common/emu_window.h
index 6c2b598f6..4cb94fed1 100644
--- a/src/common/emu_window.h
+++ b/src/common/emu_window.h
@@ -9,17 +9,33 @@
 #include "common/string_util.h"
 #include "common/key_map.h"
 
-// Abstraction class used to provide an interface between emulation code and the frontend (e.g. SDL, 
-//  QGLWidget, GLFW, etc...)
+/**
+ * Abstraction class used to provide an interface between emulation code and the frontend
+ * (e.g. SDL, QGLWidget, GLFW, etc...).
+ *
+ * Design notes on the interaction between EmuWindow and the emulation core:
+ * - Generally, decisions on anything visible to the user should be left up to the GUI.
+ *   For example, the emulation core should not try to dictate some window title or size.
+ *   This stuff is not the core's business and only causes problems with regards to thread-safety
+ *   anyway.
+ * - Under certain circumstances, it may be desirable for the core to politely request the GUI
+ *   to set e.g. a minimum window size. However, the GUI should always be free to ignore any
+ *   such hints.
+ * - EmuWindow may expose some of its state as read-only to the emulation core, however care
+ *   should be taken to make sure the provided information is self-consistent. This requires
+ *   some sort of synchronization (most of this is still a TODO).
+ * - DO NOT TREAT THIS CLASS AS A GUI TOOLKIT ABSTRACTION LAYER. That's not what it is. Please
+ *   re-read the upper points again and think about it if you don't see this.
+ */
 class EmuWindow
 {
-
 public:
-    /// Data structure to store an emuwindow configuration
+    /// Data structure to store emuwindow configuration
     struct WindowConfig {
         bool    fullscreen;
         int     res_width;
         int     res_height;
+        std::pair<unsigned,unsigned> min_client_area_size;
     };
 
     /// Swap buffers to display the next frame
@@ -42,52 +58,96 @@ public:
     /// Signals a key release action to the HID module
     static void KeyReleased(KeyMap::HostDeviceKey key);
 
-    WindowConfig GetConfig() const {
-        return m_config;
+    /**
+     * Returns currently active configuration.
+     * @note Accesses to the returned object need not be consistent because it may be modified in another thread
+     */
+    const WindowConfig& GetActiveConfig() const {
+        return active_config;
     }
 
+    /**
+     * Requests the internal configuration to be replaced by the specified argument at some point in the future.
+     * @note This method is thread-safe, because it delays configuration changes to the GUI event loop. Hence there is no guarantee on when the requested configuration will be active.
+     */
     void SetConfig(const WindowConfig& val) {
-        m_config = val;
-    }
-    
-    int GetClientAreaWidth() const { 
-        return m_client_area_width;
+        config = val;
     }
 
-    void SetClientAreaWidth(const int val) {
-        m_client_area_width = val;
+    /**
+      * Gets the framebuffer size in pixels.
+      * @note This method is thread-safe
+      */
+    const std::pair<unsigned,unsigned> GetFramebufferSize() const {
+        return framebuffer_size;
     }
 
-    int GetClientAreaHeight() const {
-        return m_client_area_height;
+    /**
+     * Gets window client area width in logical coordinates.
+     * @note For high-DPI systems, this is smaller than the framebuffer size.
+     * @note This method is thread-safe
+     */
+    std::pair<unsigned,unsigned> GetClientAreaSize() const {
+        return std::make_pair(client_area_width, client_area_height);
     }
 
-    void SetClientAreaHeight(const int val) {
-        m_client_area_height = val;
+protected:
+    EmuWindow()
+    {
+        // TODO: Find a better place to set this.
+        config.min_client_area_size = std::make_pair(400u, 480u);
+        active_config = config;
     }
+    virtual ~EmuWindow() {}
 
-    std::string GetWindowTitle() const { 
-        return m_window_title;
+    /**
+     * Processes any pending configuration changes from the last SetConfig call.
+     * This method invokes OnMinimalClientAreaChangeRequest if the corresponding configuration
+     * field changed.
+     * @note Implementations will usually want to call this from the GUI thread.
+     * @todo Actually call this in existing implementations.
+     */
+    void ProcessConfigurationChanges() {
+        // TODO: For proper thread safety, we should eventually implement a proper
+        // multiple-writer/single-reader queue...
+
+        if (config.min_client_area_size != active_config.min_client_area_size) {
+            OnMinimalClientAreaChangeRequest(config.min_client_area_size);
+            config.min_client_area_size = active_config.min_client_area_size;
+        }
     }
-    
-    void SetWindowTitle(std::string val) {
-        m_window_title = val;
+
+    /**
+     * Update internal framebuffer size with the given parameter.
+     * @note EmuWindow implementations will usually use this in window resize event handlers.
+     */
+    void NotifyFramebufferSizeChanged(const std::pair<unsigned,unsigned>& size) {
+        framebuffer_size = size;
     }
 
-protected:
-    EmuWindow():
-        m_window_title(Common::StringFromFormat("Citra | %s-%s", Common::g_scm_branch, Common::g_scm_desc)),
-        m_client_area_width(640),
-        m_client_area_height(480)
-    {}
-    virtual ~EmuWindow() {}
+    /**
+     * Update internal client area size with the given parameter.
+     * @note EmuWindow implementations will usually use this in window resize event handlers.
+     */
+    void NotifyClientAreaSizeChanged(const std::pair<unsigned,unsigned>& size) {
+        client_area_width = size.first;
+        client_area_height = size.second;
+    }
 
-    std::string m_window_title;     ///< Current window title, should be used by window impl.
+private:
+    /**
+     * Handler called when the minimal client area was requested to be changed via SetConfig.
+     * For the request to be honored, EmuWindow implementations will usually reimplement this function.
+     */
+    virtual void OnMinimalClientAreaChangeRequest(const std::pair<unsigned,unsigned>& minimal_size) {
+        // By default, ignore this request and do nothing.
+    }
 
-    int m_client_area_width;        ///< Current client width, should be set by window impl.
-    int m_client_area_height;       ///< Current client height, should be set by window impl.
+    std::pair<unsigned,unsigned> framebuffer_size;
 
-private:
-    WindowConfig m_config;                ///< Internal configuration
+    unsigned client_area_width;    ///< Current client width, should be set by window impl.
+    unsigned client_area_height;   ///< Current client height, should be set by window impl.
 
+    WindowConfig config;         ///< Internal configuration (changes pending for being applied in ProcessConfigurationChanges)
+    WindowConfig active_config;  ///< Internal active configuration
 };
diff --git a/src/common/log.h b/src/common/log.h
index bfd73f8a5..822cd21eb 100644
--- a/src/common/log.h
+++ b/src/common/log.h
@@ -69,6 +69,7 @@ enum LOG_TYPE {
     HW,
     TIME,
     NETPLAY,
+    GUI,
 
     NUMBER_OF_LOGS // Must be last
 };
diff --git a/src/common/log_manager.cpp b/src/common/log_manager.cpp
index 4d590d98f..687f4e337 100644
--- a/src/common/log_manager.cpp
+++ b/src/common/log_manager.cpp
@@ -75,6 +75,7 @@ LogManager::LogManager()
     m_Log[LogTypes::ACTIONREPLAY]       = new LogContainer("ActionReplay",      "ActionReplay");
     m_Log[LogTypes::MEMCARD_MANAGER]    = new LogContainer("MemCard Manager",   "MemCard Manager");
     m_Log[LogTypes::NETPLAY]            = new LogContainer("NETPLAY",           "Netplay");
+    m_Log[LogTypes::GUI]                = new LogContainer("GUI",               "GUI");
 
     m_fileLog = new FileLogListener(FileUtil::GetUserPath(F_MAINLOG_IDX).c_str());
     m_consoleLog = new ConsoleListener();
diff --git a/src/common/math_util.h b/src/common/math_util.h
index b32e7bb14..b10a25c13 100644
--- a/src/common/math_util.h
+++ b/src/common/math_util.h
@@ -7,6 +7,7 @@
 #include "common/common.h"
 
 #include <algorithm>
+#include <type_traits>
 #include <vector>
 
 namespace MathUtil
@@ -109,11 +110,11 @@ struct Rectangle
     Rectangle(T theLeft, T theTop, T theRight, T theBottom)
         : left(theLeft), top(theTop), right(theRight), bottom(theBottom)
     { }
-    
+
     bool operator==(const Rectangle& r) { return left==r.left && top==r.top && right==r.right && bottom==r.bottom; }
 
-    T GetWidth() const { return abs(right - left); }
-    T GetHeight() const { return abs(bottom - top); }
+    T GetWidth() const { return std::abs(static_cast<typename std::make_signed<T>::type>(right - left)); }
+    T GetHeight() const { return std::abs(static_cast<typename std::make_signed<T>::type>(bottom - top)); }
 
     // If the rectangle is in a coordinate system with a lower-left origin, use
     // this Clamp.
@@ -127,7 +128,7 @@ struct Rectangle
 
     // If the rectangle is in a coordinate system with an upper-left origin,
     // use this Clamp.
-    void ClampUL(T x1, T y1, T x2, T y2) 
+    void ClampUL(T x1, T y1, T x2, T y2)
     {
         if (left < x1) left = x1;
         if (right > x2) right = x2;