Work on line wrapping.

Rather than storing a needWrap flag, there is now a record of the last line
wrapped, so if a change requires some rewrapping then the wrapping is only
performed for the line of the change and subsequent lines.
If a change in styling spills off the end of a line, such as occurs by
starting a multiline comment, that style change may change the width of
subsequent text so rewrapping is performed.
When window resized, rewrap only done when width changed as resize may be
only vertical.

1 files changed, 33 insertions, 18 deletions

diff --git a/src/Editor.cxx b/src/Editor.cxx
index abdd46fdd..f9afa81a1 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -120,7 +120,7 @@ Editor::Editor() {
 
 	wrapState = eWrapNone;
 	wrapWidth = wrapWidthInfinite;
-	needWrap = true;
+	docLineLastWrapped = -1;
 }
 
 Editor::~Editor() {
@@ -748,12 +748,16 @@ void Editor::InvalidateCaret() {
 		InvalidateRange(currentPos, currentPos + 1);
 }
 
+void Editor::NeedWrapping(int docLineStartWrapping) {
+	docLineLastWrapped = docLineStartWrapping - 1;
+}
+
 // Check if wrapping needed and perform any needed wrapping.
 // Return true if wrapping occurred.
 bool Editor::WrapLines(int *goodTopLine) {
 	*goodTopLine = topLine;
 	bool wrapOccurred = false;
-	if (needWrap) {
+	if (docLineLastWrapped < pdoc->LinesTotal()) {
 		if (wrapState == eWrapNone) {
 			if (wrapWidth != wrapWidthInfinite) {
 				wrapWidth = wrapWidthInfinite;
@@ -762,6 +766,7 @@ bool Editor::WrapLines(int *goodTopLine) {
 				}
 				wrapOccurred = true;
 			}
+			docLineLastWrapped = 0x7ffffff;
 		} else {
 			int lineDocTop = cs.DocFromDisplay(topLine);
 			int subLineTop = topLine - cs.DisplayFromDoc(lineDocTop);
@@ -773,10 +778,12 @@ bool Editor::WrapLines(int *goodTopLine) {
 			pdoc->EnsureStyledTo(pdoc->Length());
 			AutoSurface surface(IsUnicodeMode());
 			if (surface) {
-				for (int lineDoc=0; lineDoc<pdoc->LinesTotal(); lineDoc++) {
+				int lastLineToWrap = pdoc->LinesTotal();
+				while (docLineLastWrapped <= lastLineToWrap) {
+					docLineLastWrapped++;
 					LineLayout ll;
-					LayoutLine(lineDoc, surface, vs, ll, wrapWidth);
-					if (cs.SetHeight(lineDoc, ll.lines))
+					LayoutLine(docLineLastWrapped, surface, vs, ll, wrapWidth);
+					if (cs.SetHeight(docLineLastWrapped, ll.lines))
 						wrapOccurred = true;
 				}
 			}
@@ -787,7 +794,6 @@ bool Editor::WrapLines(int *goodTopLine) {
 				*goodTopLine += cs.GetHeight(lineDocTop);
 		}
 	}
-	needWrap = false;
 	return wrapOccurred;
 }
 
@@ -1506,7 +1512,7 @@ void Editor::Paint(Surface *surfaceWindow, PRectangle rcArea) {
 
 	// Ensure we are styled as far as we are painting.
 	pdoc->EnsureStyledTo(endPosPaint);
-
+	bool paintAbandonedByStyling = paintState == paintAbandoned;
 	if (needUpdateUI) {
 		NotifyUpdateUI();
 		needUpdateUI = false;
@@ -1525,7 +1531,11 @@ void Editor::Paint(Surface *surfaceWindow, PRectangle rcArea) {
 		// outside the current painting rectangle
 		//Platform::DebugPrintf("Abandoning paint\n");
 		if (wrapState != eWrapNone) {
-			needWrap = true;
+			if (paintAbandonedByStyling) {
+				// Styling has spilled over a line end, such as occurs by starting a multiline 
+				// comment. The width of subsequent text may have changed, so rewrap.
+				NeedWrapping(cs.DocFromDisplay(topLine));
+			}
 		}
 		return;
 	}
@@ -1884,11 +1894,16 @@ void Editor::SetScrollBars() {
 }
 
 void Editor::ChangeSize() {
-	needWrap = true;
 	DropGraphics();
 	SetScrollBars();
 	if (wrapState != eWrapNone) {
-		Redraw();
+		PRectangle rcTextArea = GetClientRectangle();
+		rcTextArea.left = vs.fixedColumnWidth;
+		rcTextArea.right -= vs.rightMarginWidth;
+		if (wrapWidth != rcTextArea.Width()) {
+			NeedWrapping();
+			Redraw();
+		}
 	}
 }
 
@@ -2236,21 +2251,21 @@ void Editor::CheckModificationForWrap(DocModification mh) {
 	if ((mh.modificationType & SC_MOD_INSERTTEXT) ||
 		(mh.modificationType & SC_MOD_DELETETEXT)) {
 		if (wrapState != eWrapNone) {
+			int lineDoc = pdoc->LineFromPosition(mh.position);
 			if (mh.linesAdded == 0) {
-				int lineDoc = pdoc->LineFromPosition(mh.position);
 				AutoSurface surface(IsUnicodeMode());
 				if (surface) {
 					LineLayout ll;
 					LayoutLine(lineDoc, surface, vs, ll, wrapWidth);
 					if (cs.GetHeight(lineDoc) != ll.lines) {
-						needWrap = true;
+						NeedWrapping(lineDoc);
 						Redraw();
 					}
 				} else {
-					needWrap = true;
+					NeedWrapping(lineDoc);
 				}
 			} else {
-				needWrap = true;
+				NeedWrapping(lineDoc);
 			}
 		}
 	}
@@ -4017,13 +4032,13 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 
 	case SCI_SETMARGINLEFT:
 		vs.leftMarginWidth = lParam;
-		needWrap = true;
+		NeedWrapping();
 		InvalidateStyleRedraw();
 		break;
 
 	case SCI_SETMARGINRIGHT:
 		vs.rightMarginWidth = lParam;
-		needWrap = true;
+		NeedWrapping();
 		InvalidateStyleRedraw();
 		break;
 
@@ -4326,7 +4341,7 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 
 	case SCI_SETWRAPMODE:
 		wrapState = (wParam == SC_WRAP_WORD) ? eWrapWord : eWrapNone;
-		needWrap = true;
+		NeedWrapping();
 		xOffset = 0;
 		InvalidateStyleRedraw();
 		ReconfigureScrollBars();
@@ -4451,7 +4466,7 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 	case SCI_SETMARGINWIDTHN:
 		if (ValidMargin(wParam)) {
 			vs.ms[wParam].width = lParam;
-			needWrap = true;
+			NeedWrapping();
 			InvalidateStyleRedraw();
 		}
 		break;