Freeze the scrollbar while editor is open in property browser.

Before this commit, the scrollbar would move freely, without changing
the position of the viewport. It would be reset after editing is
finished.

src/platform/guimac.mm

@@ -952,9 +952,10 @@ public:
     }
 
     void SetScrollbarPosition(double pos) override {
-        if(pos > ssView.scrollerMax) {
+        if(pos > ssView.scrollerMax)
             pos = ssView.scrollerMax;
-        }
+        if(GetScrollbarPosition() == pos)
+            return;
         [nsScroller setDoubleValue:(pos / (ssView.scrollerMax - ssView.scrollerMin))];
         if(onScrollbarAdjusted) {
             onScrollbarAdjusted(pos);

src/platform/guiwin.cpp

@@ -1354,7 +1354,11 @@ public:
         SCROLLINFO si = {};
         si.cbSize = sizeof(si);
         si.fMask  = SIF_POS;
-        si.nPos   = (UINT)(pos * SCROLLBAR_UNIT);
+        sscheck(GetScrollInfo(hWindow, SB_VERT, &si));
+        if(si.nPos == (int)(pos * SCROLLBAR_UNIT))
+            return;
+
+        si.nPos   = (int)(pos * SCROLLBAR_UNIT);
         sscheck(SetScrollInfo(hWindow, SB_VERT, &si, /*redraw=*/TRUE));
 
         // Windows won't synthesize a WM_VSCROLL for us here.

src/textwin.cpp

@@ -1129,8 +1129,10 @@ void TextWindow::MouseLeave() {
 }
 
 void TextWindow::ScrollbarEvent(double newPos) {
-    if(window->IsEditorVisible())
+    if(window->IsEditorVisible()) {
+        window->SetScrollbarPosition(scrollPos);
         return;
+    }
 
     int bottom = top[rows-1] + 2;
     newPos = min((int)newPos, bottom - halfRows);