Add GetWordAtScreenPos() - get the word at a screen position (e.g. from ImGui::GetMousePos())

Author: pthom

TextEditor.cpp

@@ -91,6 +91,7 @@ void TextEditor::render(const char* title, const ImVec2& size, bool border) {
 
 	// get current position and total/visible editor size
 	auto pos = ImGui::GetCursorScreenPos();
+	lastRenderOrigin = pos;
 	auto totalSize = ImVec2(textOffset + document.getMaxColumn() * glyphSize.x + cursorWidth, document.size() * glyphSize.y);
 	auto region = ImGui::GetContentRegionAvail();
 	auto visibleSize = ImGui::CalcItemSize(size, region.x, region.y); // messing with Dear ImGui internals
@@ -1306,6 +1307,30 @@ std::string TextEditor::getCursorText(size_t cursor) const {
 }
 
 
+//
+//	TextEditor::GetWordAtScreenPos
+//
+
+std::string TextEditor::GetWordAtScreenPos(const ImVec2& screenPos) const {
+	// Convert screen position to local coordinates using the origin saved during last Render()
+	auto local = screenPos - lastRenderOrigin;
+
+	// Convert to text coordinates using the same logic as handleMouseInteractions()
+	Coordinate glyphCoordinate;
+	Coordinate cursorCoordinate;
+	document.normalizeCoordinate(
+		local.y / glyphSize.y,
+		(local.x - textOffset) / glyphSize.x,
+		glyphCoordinate,
+		cursorCoordinate);
+
+	// Find word boundaries and extract text
+	auto start = document.findWordStart(glyphCoordinate);
+	auto end = document.findWordEnd(glyphCoordinate);
+	return document.getSectionText(start, end);
+}
+
+
 //
 //	TextEditor::makeCursorVisible
 //

TextEditor.h

@@ -148,6 +148,9 @@ class TextEditor {
 	inline void GetMainCursor(int& line, int& column) const { return getCursor(line, column, cursors.getMainIndex()); }
 	inline void GetCurrentCursor(int& line, int& column) const { return getCursor(line, column, cursors.getCurrentIndex()); }
 
+	// get the word at a screen position (e.g. from ImGui::GetMousePos()) - uses the origin saved during the last Render() call
+	std::string GetWordAtScreenPos(const ImVec2& screenPos) const;
+
 	// scrolling support
 	enum class Scroll {
 		alignTop,
@@ -1281,6 +1284,7 @@ class TextEditor {
 	ImFont* font;
 	float fontSize;
 	ImVec2 glyphSize;
+	ImVec2 lastRenderOrigin;
 	float lineNumberLeftOffset;
 	float lineNumberRightOffset;
 	float decorationOffset;