Add the ability to limit-rate the dashboard updating (#3527)

Co-authored-by: Emma Broman <emma.broman@liu.se>

include/openspace/rendering/dashboard.h

@@ -28,6 +28,7 @@
 #include <openspace/properties/propertyowner.h>
 
 #include <openspace/properties/scalar/boolproperty.h>
+#include <openspace/properties/scalar/intproperty.h>
 #include <openspace/properties/vector/ivec2property.h>
 #include <openspace/rendering/dashboarditem.h>
 #include <ghoul/glm.h>
@@ -43,6 +44,14 @@ public:
     Dashboard();
     virtual ~Dashboard() override = default;
 
+    /**
+     * Renders all of the items of this Dashboard at the provided \p penPosition. The
+     * position is provided in pixels with the top-left corner being located at (0,0). The
+     * rendering of the DashboardItems will update the \p penPosition according to where
+     * the next item should be placed.
+     *
+     * \param penPosition The location at which we want to render the dashboard items
+     */
     void render(glm::vec2& penPosition);
 
     void addDashboardItem(std::unique_ptr<DashboardItem> item);
@@ -63,8 +72,10 @@ public:
 private:
     properties::BoolProperty _isEnabled;
     properties::IVec2Property _startPositionOffset;
+    properties::IntProperty _refreshRate;
 
     std::vector<std::unique_ptr<DashboardItem>> _items;
+    std::chrono::steady_clock::time_point _lastRefresh;
 };
 
 } // openspace

include/openspace/rendering/dashboarditem.h

@@ -45,6 +45,18 @@ public:
     explicit DashboardItem(const ghoul::Dictionary& dictionary);
 
     bool isEnabled() const;
+    virtual void update() = 0;
+
+    /**
+     * Renders this DashboardItem at the provided \p penPosition. The position indicates
+     * where this DashboardItem should render itself and is provided in pixel-coordinates
+     * with the top-left corner of the screen being at (0,0). Each derived subclass shall
+     * update the \p penPosition according to the items that it should render. If, for
+     * example, a single line of text is rendered, the \p penPosition shall be updated by
+     * one line's worth of vertical separation.
+     *
+     * \p penPosition The position at which this DashboardItem should be rendered
+     */
     virtual void render(glm::vec2& penPosition) = 0;
 
     virtual glm::vec2 size() const = 0;

include/openspace/rendering/dashboardtextitem.h

@@ -42,6 +42,8 @@ public:
     explicit DashboardTextItem(const ghoul::Dictionary& dictionary, float fontSize = 10.f,
         const std::string& fontName = "Mono");
 
+    void render(glm::vec2& penPosition) override;
+
     static documentation::Documentation Documentation();
 
 protected:
@@ -49,6 +51,7 @@ protected:
     properties::FloatProperty _fontSize;
 
     std::shared_ptr<ghoul::fontrendering::Font> _font;
+    std::string _buffer;
 };
 
 } // openspace