Bug [#1224]. Remember selection in undo history. SCI_SETSELECTIONUNDOHISTORY.

1 files changed, 59 insertions, 0 deletions

diff --git a/src/EditModel.cxx b/src/EditModel.cxx
index 13b3da5b0..60848e6dc 100644
--- a/src/EditModel.cxx
+++ b/src/EditModel.cxx
@@ -58,6 +58,54 @@ using namespace Scintilla::Internal;
 Caret::Caret() noexcept :
 	active(false), on(false), period(500) {}
 
+SelectionSimple::SelectionSimple(const Selection &sel) {
+	selType = sel.selType;
+	if (sel.IsRectangular()) {
+		// rectangular or thin
+		// Could be large so don't remember each range, just the rectangular bounds then reconstitute when undone
+		rangeRectangular = sel.RectangularCopy();
+	} else {
+		ranges = sel.RangesCopy();
+	}
+	mainRange = sel.Main();
+}
+
+void ModelState::RememberSelectionForUndo(int index, const Selection &sel) {
+	historyForUndo.indexCurrent = index;
+	historyForUndo.ssCurrent = SelectionSimple(sel);
+}
+
+void ModelState::ForgetSelectionForUndo() noexcept {
+	historyForUndo.indexCurrent = -1;
+}
+
+void ModelState::RememberSelectionOntoStack(int index) {
+	if ((historyForUndo.indexCurrent >= 0) && (index == historyForUndo.indexCurrent + 1)) {
+		// Don't overwrite initial selection save if most recent action was coalesced
+		historyForUndo.stack[index] = historyForUndo.ssCurrent;
+	}
+}
+
+void ModelState::RememberSelectionForRedoOntoStack(int index, const Selection &sel) {
+	historyForRedo.stack[index] = SelectionSimple(sel);
+}
+
+const SelectionSimple *ModelState::SelectionFromStack(int index, UndoRedo history) const {
+	const SelectionHistory &sh = history == UndoRedo::undo ? historyForUndo : historyForRedo;
+	std::map<int, SelectionSimple>::const_iterator it = sh.stack.find(index);
+	if (it != sh.stack.end()) {
+		return &it->second;
+	}
+	return {};
+}
+
+void ModelState::TruncateUndo(int index) {
+	std::map<int, SelectionSimple>::iterator itUndo = historyForUndo.stack.find(index);
+	historyForUndo.stack.erase(itUndo, historyForUndo.stack.end());
+	std::map<int, SelectionSimple>::iterator itRedo = historyForRedo.stack.find(index);
+	historyForRedo.stack.erase(itRedo, historyForRedo.stack.end());
+}
+
 EditModel::EditModel() : braces{} {
 	inOverstrike = false;
 	xOffset = 0;
@@ -131,3 +179,14 @@ InSelection EditModel::LineEndInSelection(Sci::Line lineDoc) const {
 int EditModel::GetMark(Sci::Line line) const {
 	return pdoc->GetMark(line, FlagSet(changeHistoryOption, ChangeHistoryOption::Markers));
 }
+
+void EditModel::EnsureModelState() {
+	if (!modelState && rememberingSelectionForUndo) {
+		if (ViewStateShared vss = pdoc->GetViewState(this)) {
+			modelState = std::dynamic_pointer_cast<ModelState>(vss);
+		} else {
+			modelState = std::make_shared<ModelState>();
+			pdoc->SetViewState(this, std::static_pointer_cast<ViewState>(modelState));
+		}
+	}
+}