You can move around a document with Click+Drag!

Uses some scary C++11 features, so no idea if this will break the CS Lab machines
and their ancient version of gcc.

diff --git a/src/main.h b/src/main.h
index ee8076a..c7d5eca 100644 (file)
--- a/src/main.h
+++ b/src/main.h
@@ -12,6 +12,31 @@ inline void MainLoop(Document & doc)
 {
        View view(doc);
        Screen scr;
+       scr.SetMouseHandler([&](int x, int y, int buttons, int wheel)
+       {
+               static bool oldButtonDown = false;
+               static int oldx, oldy;
+               if (buttons && !oldButtonDown)
+               {
+                       // We're beginning a drag.
+                       oldButtonDown = true;
+                       oldx = x;
+                       oldy = y;
+                       scr.SetMouseCursor(Screen::CursorMove);
+               }
+               if (buttons)
+               {
+                       view.Translate(Real(oldx-x)/Real(scr.ViewportWidth()), Real(oldy-y)/Real(scr.ViewportHeight()));
+               }
+               else
+               {
+                       oldButtonDown = false;
+                       scr.SetMouseCursor(Screen::CursorArrow);
+               }
+               oldx = x;
+               oldy = y;
+       }
+       );
        while (scr.PumpEvents())
        {
                view.Render();

diff --git a/src/screen.cpp b/src/screen.cpp
index 6909be2..d924c06 100644 (file)
--- a/src/screen.cpp
+++ b/src/screen.cpp
@@ -18,6 +18,8 @@ Screen::Screen()
        }
 
        m_gl_context = SDL_GL_CreateContext(m_window);
+       
+       ResizeViewport(800, 600);
 
 }
 
@@ -55,6 +57,19 @@ bool Screen::PumpEvents()
                                break;
                        }
                        break;
+               case SDL_MOUSEMOTION:
+                       if (m_mouse_handler)
+                       {
+                               m_mouse_handler(evt.motion.x, evt.motion.y,evt.motion.state, 0);
+                       }
+                       break;
+               case SDL_MOUSEBUTTONDOWN:
+               case SDL_MOUSEBUTTONUP:
+                       if (m_mouse_handler)
+                       {
+                               m_mouse_handler(evt.button.x, evt.button.y, evt.button.state, 0);
+                       }
+                       break;
                default:
                        break;
                }
@@ -62,6 +77,23 @@ bool Screen::PumpEvents()
        return no_quit_requested;
 }
 
+void Screen::SetMouseCursor(Screen::MouseCursors cursor)
+{
+       SDL_SystemCursor system_cursor_id = SDL_SYSTEM_CURSOR_ARROW;
+       switch (cursor)
+       {
+       case CursorArrow: system_cursor_id = SDL_SYSTEM_CURSOR_ARROW; break;
+       case CursorWait: system_cursor_id = SDL_SYSTEM_CURSOR_WAIT; break;
+       case CursorWaitArrow: system_cursor_id = SDL_SYSTEM_CURSOR_WAITARROW; break;
+       case CursorMove: system_cursor_id = SDL_SYSTEM_CURSOR_SIZEALL; break;
+       case CursorHand: system_cursor_id = SDL_SYSTEM_CURSOR_HAND; break;
+       default: break;
+       }
+       SDL_Cursor *system_cursor = SDL_CreateSystemCursor(system_cursor_id);
+       SDL_SetCursor(system_cursor);
+       //TODO: Check if we need to free the system cursors.
+}
+
 void Screen::Present()
 {
        SDL_GL_SwapWindow(m_window);

diff --git a/src/screen.h b/src/screen.h
index ebe9da2..8452efc 100644 (file)
--- a/src/screen.h
+++ b/src/screen.h
@@ -3,6 +3,8 @@
 
 #include <SDL.h>
 
+#include <functional>
+
 namespace IPDF
 {
        /*
@@ -24,14 +26,34 @@ namespace IPDF
                // Get the current width/height of the window's viewport.
                int ViewportWidth() { return m_viewport_width; }
                int ViewportHeight() { return m_viewport_height; }
+               
+               // Handle mouse input.
+               typedef std::function<void(int x, int y, int button, int wheel)> MouseHandler;
+               void SetMouseHandler(MouseHandler handler)
+               {
+                       m_mouse_handler = handler;
+               }
+               
+               enum MouseCursors
+               {
+                       CursorArrow,
+                       CursorWait,
+                       CursorWaitArrow,
+                       CursorMove,
+                       CursorHand
+               };
+               void SetMouseCursor(MouseCursors cursor);
        private:
                void ResizeViewport(int width, int height);
+               
+               MouseHandler m_mouse_handler;
 
                int m_viewport_width;
                int m_viewport_height;
                SDL_Window *m_window;
                SDL_GLContext m_gl_context;
        };
+
 }
 
 #endif // _SCREEN_H

diff --git a/src/view.cpp b/src/view.cpp
index ed62704..f78ec40 100644 (file)
--- a/src/view.cpp
+++ b/src/view.cpp
@@ -5,6 +5,12 @@
 using namespace IPDF;
 using namespace std;
 
+void View::Translate(Real x, Real y)
+{
+       m_bounds.x += x;
+       m_bounds.y += y;
+}
+
 void View::Render()
 {
        static bool debug_output_done = false;

diff --git a/src/view.h b/src/view.h
index 9a519b0..cc09a89 100644 (file)
--- a/src/view.h
+++ b/src/view.h
@@ -13,6 +13,8 @@ namespace IPDF
                        virtual ~View() {}
 
                        void Render();
+                       
+                       void Translate(Real x, Real y);
                
                private:
                        Document & m_document;