2 files changed, 22 insertions, 7 deletions

diff --git a/src/Editor.cxx b/src/Editor.cxx
index e9a30ee72..89c67b433 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -175,7 +175,8 @@ Editor::Editor() {
 
 	lengthForEncode = -1;
 
-	needUpdateUI = true;
+	needUpdateUI = 0;
+	ContainerNeedsUpdate(SC_UPDATE_CONTENT);
 	braces[0] = invalidPosition;
 	braces[1] = invalidPosition;
 	bracesMatchStyle = STYLE_BRACEBAD;
@@ -434,7 +435,10 @@ int Editor::LineFromLocation(Point pt) {
 }
 
 void Editor::SetTopLine(int topLineNew) {
-	topLine = topLineNew;
+	if (topLine != topLineNew) {
+		topLine = topLineNew;
+		ContainerNeedsUpdate(SC_UPDATE_V_SCROLL);
+	}
 	posTopLine = pdoc->LineStart(cs.DocFromDisplay(topLine));
 }
 
@@ -741,7 +745,7 @@ void Editor::InvalidateSelection(SelectionRange newMain, bool invalidateWholeSel
 			lastAffected = Platform::Maximum(lastAffected, sel.Range(r).anchor.Position());
 		}
 	}
-	needUpdateUI = true;
+	ContainerNeedsUpdate(SC_UPDATE_SELECTION);
 	InvalidateRange(firstAffected, lastAffected);
 }
 
@@ -982,6 +986,7 @@ void Editor::HorizontalScrollTo(int xPos) {
 		xPos = 0;
 	if ((wrapState == eWrapNone) && (xOffset != xPos)) {
 		xOffset = xPos;
+		ContainerNeedsUpdate(SC_UPDATE_H_SCROLL);
 		SetHorizontalScrollPos();
 		RedrawRect(GetClientRectangle());
 	}
@@ -1291,6 +1296,7 @@ void Editor::SetXYScroll(XYScrollPosition newXY) {
 		}
 		if (newXY.xOffset != xOffset) {
 			xOffset = newXY.xOffset;
+			ContainerNeedsUpdate(SC_UPDATE_H_SCROLL);
 			if (newXY.xOffset > 0) {
 				PRectangle rcText = GetTextRectangle();
 				if (horizontalScrollBarVisible &&
@@ -3307,7 +3313,7 @@ void Editor::Paint(Surface *surfaceWindow, PRectangle rcArea) {
 		surfaceWindow->SetPalette(&palTemp, true);
 
 		NotifyUpdateUI();
-		needUpdateUI = false;
+		needUpdateUI = 0;
 
 		RefreshStyleData();
 		RefreshPixMaps(surfaceWindow);
@@ -4213,6 +4219,7 @@ void Editor::NotifyHotSpotReleaseClick(int position, bool shift, bool ctrl, bool
 void Editor::NotifyUpdateUI() {
 	SCNotification scn = {0};
 	scn.nmhdr.code = SCN_UPDATEUI;
+	scn.updated = needUpdateUI;
 	NotifyParent(scn);
 }
 
@@ -4329,7 +4336,7 @@ static inline int MovePositionForDeletion(int position, int startDeletion, int l
 }
 
 void Editor::NotifyModified(Document *, DocModification mh, void *) {
-	needUpdateUI = true;
+	ContainerNeedsUpdate(SC_UPDATE_CONTENT);
 	if (paintState == painting) {
 		CheckForChangeOutsidePaint(Range(mh.position, mh.position + mh.length));
 	}
@@ -4611,6 +4618,11 @@ void Editor::NotifyMacroRecord(unsigned int iMessage, uptr_t wParam, sptr_t lPar
 	NotifyParent(scn);
 }
 
+// Something has changed that the container should know about
+void Editor::ContainerNeedsUpdate(int flags) {
+	needUpdateUI |= flags;
+}
+
 /**
  * Force scroll and keep position relative to top of window.
  *
@@ -6338,7 +6350,7 @@ void Editor::IdleStyling() {
 
 	if (needUpdateUI) {
 		NotifyUpdateUI();
-		needUpdateUI = false;
+		needUpdateUI = 0;
 	}
 	styleNeeded.Reset();
 }
@@ -6995,6 +7007,7 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 
 	case SCI_SETXOFFSET:
 		xOffset = wParam;
+		ContainerNeedsUpdate(SC_UPDATE_H_SCROLL);
 		SetHorizontalScrollPos();
 		Redraw();
 		break;
@@ -7459,6 +7472,7 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 			break;
 		}
 		xOffset = 0;
+		ContainerNeedsUpdate(SC_UPDATE_H_SCROLL);
 		InvalidateStyleRedraw();
 		ReconfigureScrollBars();
 		break;
diff --git a/src/Editor.h b/src/Editor.h
index 288addee0..a618e1e40 100644
--- a/src/Editor.h
+++ b/src/Editor.h
@@ -208,7 +208,7 @@ protected:	// ScintillaBase subclass needs access to much of Editor
 	int posTopLine;
 	int lengthForEncode;
 
-	bool needUpdateUI;
+	int needUpdateUI;
 	Position braces[2];
 	int bracesMatchStyle;
 	int highlightGuideColumn;
@@ -438,6 +438,7 @@ protected:	// ScintillaBase subclass needs access to much of Editor
 	void NotifyErrorOccurred(Document *doc, void *userData, int status);
 	void NotifyMacroRecord(unsigned int iMessage, uptr_t wParam, sptr_t lParam);
 
+	void ContainerNeedsUpdate(int flags);
 	void PageMove(int direction, Selection::selTypes sel=Selection::noSel, bool stuttered = false);
 	enum { cmSame, cmUpper, cmLower } caseMap;
 	virtual std::string CaseMapString(const std::string &s, int caseMapping);