WIP: added minimal text editor

Author: Pier-Olivier Boulianne

Core/Source/Lux/Vendor/TextDiff.cpp

@@ -0,0 +1,146 @@
+/*
+MIT License
+
+Copyright (c) 2024-2026 Johan A. Goossens. All rights reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+//	TextDiff - A syntax highlighting text diff widget for Dear ImGui.
+//	Copyright (c) 2024-2026 Johan A. Goossens. All rights reserved.
+//
+//	This work is licensed under the terms of the MIT license.
+//	For a copy, see <https://opensource.org/licenses/MIT>.
+
+
+#pragma once
+
+
+//
+//	Include files
+//
+
+#include "TextEditor.h"
+
+//
+//	TextDiff
+//
+
+class TextDiff : public TextEditor {
+public:
+	// constructor
+	TextDiff();
+
+	// specify visual mode (combined is default)
+	inline void SetSideBySideMode(bool flag) { sideBySideMode = flag; }
+	inline bool GetSideBySideMode() const { return sideBySideMode; }
+
+	// specify the text to be compared (using UTF-8 encoded strings)
+	void SetText(const std::string_view& left, const std::string_view& right);
+
+	// specify a new language
+	void SetLanguage(const Language* l);
+
+	// specify the background color for added/deleted lines
+	inline void SetColors(ImU32 ac, ImU32 dc) { addedColor = ac; deletedColor = dc; }
+
+	// render the text editor in a Dear ImGui context
+	void Render(const char* title, const ImVec2& size=ImVec2(), bool border=false);
+
+	// block/hide certain API calls
+	inline void SetReadOnlyEnabled(bool /* value */) {}
+	inline void SetShowLineNumbersEnabled(bool /* value */) {}
+	inline void SetShowMatchingBrackets(bool /* value */) {}
+
+	inline void AddMarker(int /* line */, ImU32 /* lineNumberColor */, ImU32 /* textColor */, const std::string_view& /* lineNumberTooltip */, const std::string_view& /* textTooltip */) {}
+	inline void ClearMarkers() {}
+
+	inline void SetLineDecorator(float /* width */, std::function<void(Decorator& decorator)> /* callback */) {}
+	inline void ClearLineDecorator() {}
+
+	inline void SetLineNumberContextMenuCallback(std::function<void(int line)> /* callback */) {}
+	inline void ClearLineNumberContextMenuCallback() {}
+
+	inline void SetTextContextMenuCallback(std::function<void(int line, int column)> /* callback */) {}
+	inline void ClearTextContextMenuCallback() {}
+
+private:
+	// rendering mode
+	bool sideBySideMode = false;
+
+	// the two documents being compared
+	TextEditor::Document leftDocument;
+	TextEditor::Document rightDocument;
+
+	// number of digits in line numbers
+	int leftLineNumberDigits;
+	int rightLineNumberDigits;
+
+	// status of text line
+	enum class LineStatus {
+		common,
+		added,
+		deleted
+	};
+
+	// information about a single visible line
+	class LineInfo {
+	public:
+		LineInfo(size_t l, size_t r, LineStatus s) : leftLine(l), rightLine(r), status(s) {}
+
+		size_t leftLine;
+		size_t rightLine;
+		LineStatus status;
+	};
+
+	std::vector<LineInfo> lineInfo;
+	bool updated = false;
+
+	// colors
+	ImU32 addedColor = IM_COL32(0, 150, 32, 128);
+	ImU32 deletedColor = IM_COL32(180, 0, 32, 128);
+
+	// side-by-side rendering parameters
+	float leftLineNumberWidth;
+	float rightLineNumberWidth;
+	float textColumnWidth;
+	float leftLineNumberPos;
+	float leftTextPos;
+	float rightLineNumberPos;
+	float rightTextPos;
+	float rightTextEnd;
+	float textScroll;
+
+	// split string into lines
+	void splitLines(std::vector<std::string_view>& result, const std::string_view& text);
+
+	// create a combined view of the two documents and their differences
+	void createCombinedView();
+
+	// line decorator
+	void decorateLine(TextEditor::Decorator& decorator);
+
+	// render the side-by-side mode and its parts
+	void renderSideBySide(const char* title, const ImVec2& size, bool border);
+	void renderSideBySideBackground();
+	void renderSideBySideText();
+	void renderSideBySideLine(float x, float y, TextEditor::Line& line);
+	void renderSideBySideTextScrollbars();
+	void renderSideBySideMiniMap();
+};