Add ability to scrolling in scrollareas like chat by mouse draging.

2 files changed, 62 insertions, 0 deletions

diff --git a/src/gui/widgets/scrollarea.cpp b/src/gui/widgets/scrollarea.cpp
index 2796d3ab2..3204028dc 100644
--- a/src/gui/widgets/scrollarea.cpp
+++ b/src/gui/widgets/scrollarea.cpp
@@ -47,6 +47,8 @@ ScrollArea::ScrollArea():
     gcn::ScrollArea(),
     mX(0),
     mY(0),
+    mClickX(0),
+    mClickY(0),
     mHasMouse(false),
     mOpaque(true),
     mVertexes(new GraphicsVertexes()),
@@ -64,6 +66,8 @@ ScrollArea::ScrollArea(gcn::Widget *widget):
     gcn::ScrollArea(widget),
     mX(0),
     mY(0),
+    mClickX(0),
+    mClickY(0),
     mHasMouse(false),
     mOpaque(true),
     mVertexes(new GraphicsVertexes()),
@@ -513,3 +517,56 @@ void ScrollArea::widgetMoved(const gcn::Event& event A_UNUSED)
 {
     mRedraw = true;
 }
+
+void ScrollArea::mousePressed(gcn::MouseEvent& event)
+{
+    gcn::ScrollArea::mousePressed(event);
+    if (event.getButton() == gcn::MouseEvent::LEFT)
+    {
+        mClickX = event.getX();
+        mClickY = event.getY();
+    }
+}
+
+void ScrollArea::mouseReleased(gcn::MouseEvent& event)
+{
+    if (event.getButton() == gcn::MouseEvent::LEFT && mClickX && mClickY)
+    {
+        if (!event.isConsumed())
+        {
+            int dx = event.getX() - mClickX;
+            int dy = event.getY() - mClickY;
+
+            if ((dx < 10 && dx > 0) || (dx > -10 && dx < 0))
+                dx = 0;
+
+            if ((dy < 10 && dy > 0) || (dy > -10 && dy < 0))
+                dy = 0;
+
+            if (dx)
+            {
+                int s = getHorizontalScrollAmount() + dx;
+                if (s < 0)
+                    s = 0;
+                else if (s > getHorizontalMaxScroll())
+                    s = getHorizontalMaxScroll();
+
+                setHorizontalScrollAmount(s);
+            }
+            if (dy)
+            {
+                int s = getVerticalScrollAmount() + dy;
+                if (s < 0)
+                    s = 0;
+                else if (s > getVerticalMaxScroll())
+                    s = getVerticalMaxScroll();
+
+                setVerticalScrollAmount(s);
+            }
+            mClickX = 0;
+            mClickY = 0;
+            event.consume();
+        }
+    }
+    gcn::ScrollArea::mouseReleased(event);
+}
diff --git a/src/gui/widgets/scrollarea.h b/src/gui/widgets/scrollarea.h
index 095010f3c..56e21c58c 100644
--- a/src/gui/widgets/scrollarea.h
+++ b/src/gui/widgets/scrollarea.h
@@ -112,6 +112,10 @@ class ScrollArea : public gcn::ScrollArea, public gcn::WidgetListener
          */
         void mouseExited(gcn::MouseEvent& event);
 
+        void mousePressed(gcn::MouseEvent& event);
+
+        void mouseReleased(gcn::MouseEvent& event);
+
         void widgetResized(const gcn::Event &event);
 
         void widgetMoved(const gcn::Event &event);
@@ -148,6 +152,7 @@ class ScrollArea : public gcn::ScrollArea, public gcn::WidgetListener
         static Image *buttons[4][2];
 
         int mX, mY;
+        int mClickX, mClickY;
         bool mHasMouse;
         bool mOpaque;
         GraphicsVertexes *mVertexes;