VectorEditor

A vector graphics editor built with C++17 and Qt6. Supports drawing, editing, and styling shapes on a canvas with undo/redo, clipboard operations, SVG import/export, and inline text editing.

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Features

Drawing Tools

All shape tools follow click-and-drag creation with a live transient preview:

• Rectangle and Rounded Rectangle
• Circle
• Line
• Hexagon (regular, 6 vertices computed from center + radius)
• Free Sketch (freehand polyline, records points during drag)
• Text (click to place, type inline, Enter/Escape to finish)

Selection & Manipulation

• Select Tool: Click a shape to select it (bounding box + resize handle shown).
• Move: Drag a selected shape's bounding box to reposition.
• Resize: Drag the bottom-right handle to scale.
• Clipboard: Right-click context menu with Cut, Copy, Paste, Delete.

Styling (Properties Bar)

• Stroke Width: SpinBox (1–20 px), applies to selected shape immediately.
• Stroke Color / Fill Color: QColorDialog pickers. Changes are undoable.
• Font Family / Font Size: QFontComboBox and SpinBox for text shapes.

Undo / Redo

• Full command-based undo/redo via UndoRedoManager.
• Every shape add, delete, move, resize, and property change is tracked.
• New actions clear the redo stack (linear history).

SVG Import / Export

• Open: File → Open parses an SVG file into diagram shapes (SvgParser + ShapetoTag).
• Save / Save As: File → Save exports the diagram back to SVG (RevSvgParser).
• New: File → New clears the canvas.

Supported SVG elements: <rect>, <circle>, <line>, <polyline>, <polygon>, <text>.

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Architecture

Ownership Model

• Diagram owns shapes via std::vector<std::unique_ptr<GraphicsObject>>.
• Canvas owns Diagram, SvgParser, RevSvgParser, Clipboard, UndoRedoManager via std::unique_ptr.
• Qt-managed widgets (toolbars, actions, labels) use raw pointers — Qt handles their lifetime.
• Non-owning raw pointers (curr_shape_, editing_text_shape_) for temporary references.

Class Hierarchy

GraphicsObject (abstract base)
├── Rectangle      (x, y, width, height, rx, ry)
├── Circle         (x, y, diameter — cx/cy/r derived)
├── Line           (x1, y1, x2, y2)
├── Hexagon        (x, y, diameter — 6 vertices from cx/cy/r)
├── FreeSketch     (QVector<QPoint> sketch_points_)
└── TextShape      (text_, font_, font_size_, baseline)

Virtual interface: Draw(), Contains(), Resize(), Move(), AtHandle(), DrawHandle(), SetXAnch(), SetYAnch(), Clone().

Command Pattern

• Command base stores initial_state_ and final_state_ (each a ShapeState = index + cloned shape).
• ShapeAddCmd: undo removes at index, redo re-inserts clone.
• ShapeDeleteCmd: undo re-inserts, redo removes.
• ShapeModifyCmd: undo/redo swap cloned snapshots at index.
• UndoRedoManager holds undo/redo stacks of unique_ptr<Command>.

SVG Pipeline

• Import: SvgParser::Parse() reads file line-by-line → ShapetoTag dispatches by tag name → MakeRect(), MakeCircle(), etc. push shapes to Diagram.
• Export: RevSvgParser::WriteToFile() iterates Diagram, dynamic_casts each shape → RectToTag(), CircleToTag(), etc. write SVG tags to file.
• Helper classes: AttributeGetter (extracts attribute values from tag strings), CleanStr (string trimming), DefaultAttributes (fallback values).

Canvas State Machine

InteractionMode enum drives canvas behavior:

None → DrawRect / DrawRoundedRect / DrawCircle / DrawLine /
       DrawHexagon / DrawFreeSketch / DrawText /
       TextEdit / SelectTool → OnShape → ShapeMove / ShapeResize / CutCopy

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Project Structure

Assignment_1/
├── CMakeLists.txt
├── include/                        # All headers
│   ├── canvas.h                    # Canvas widget + InteractionMode enum
│   ├── diagram.h                   # Shape collection (model)
│   ├── main_window.h               # MainWindow with toolbars/menus
│   ├── graphics_object.h           # Abstract base class
│   ├── rectangle.h / circle.h / line.h / hexagon.h
│   ├── free_sketch.h / text_shape.h
│   ├── command.h                   # Command base + ShapeState
│   ├── shape_add_cmd.h / shape_delete_cmd.h / shape_modify_cmd.h
│   ├── undo_redo.h                 # UndoRedoManager + CommandType enum
│   ├── clipboard.h
│   ├── svg_parser.h / rev_svg_parser.h / process_shape_tag.h
│   ├── attribute_getter.h / clean_str.h / default_attributes.h
│   └── ...
│
├── src/
│   ├── core/                       # Canvas (split across files) + Diagram + main
│   │   ├── canvas.cpp              # Constructor / destructor
│   │   ├── canvas_file_ops.cpp     # Open, Save, SaveAs, New, Undo, Redo
│   │   ├── canvas_setters.cpp      # SetFillColor, SetStrokeColor, SetStrokeWidth, font setters
│   │   ├── canvas_paint.cpp        # paintEvent, mouseMoveEvent
│   │   ├── canvas_mouse_press.cpp  # mousePressEvent dispatcher
│   │   ├── canvas_draw_press.cpp   # HandleDrawPress (shape creation)
│   │   ├── canvas_text_press.cpp   # HandleTextDrawPress, HandleTextEditPress
│   │   ├── canvas_select_press.cpp # HandleSelectPress, HandleOnShapePress
│   │   ├── canvas_clipboard.cpp    # HandleRightClick (context menu)
│   │   ├── canvas_mouse_release.cpp# mouseReleaseEvent
│   │   ├── canvas_key_events.cpp   # keyPressEvent (text input)
│   │   ├── diagram.cpp
│   │   └── main.cpp
│   │
│   ├── shapes/                     # Shape implementations
│   │   ├── graphics_object.cpp
│   │   ├── rectangle.cpp / circle.cpp / line.cpp / hexagon.cpp
│   │   ├── free_sketch.cpp         # Constructor, Draw, Move, Clone
│   │   ├── free_sketch_ops.cpp     # Resize, AtHandle, SetAnch
│   │   ├── text_shape.cpp          # Constructor, getters/setters, UpdateBoundingBox
│   │   ├── text_shape_draw.cpp     # Draw, DrawBbox, Contains, Resize
│   │   └── text_shape_ops.cpp      # Move, DrawHandle, AtHandle, Clone
│   │
│   ├── commands/                   # Command pattern
│   │   ├── command.cpp / clipboard.cpp / undo_redo.cpp
│   │   └── shape_add_cmd.cpp / shape_delete_cmd.cpp / shape_modify_cmd.cpp
│   │
│   ├── ui/                         # Main window
│   │   ├── main_window.cpp         # Constructor, CreateMenu, CreateToolbar, CreateColorbar
│   │   ├── main_window_actions.cpp # CreateActions (all signal/slot connections)
│   │   └── main_window_properties.cpp # CreatePropertiesBar (stroke width, font controls)
│   │
│   └── parser/                     # SVG import / export
│       ├── svg_parser.cpp
│       ├── process_shape_tag.cpp       # MakeRect, MakeCircle, MakeLine, MakeText
│       ├── process_shape_tag_complex.cpp # MakePolyline, MakePolygon
│       ├── rev_svg_parser.cpp          # Shape-to-tag converters (Rect/Circle/Line/Polyline/Polygon/Text)
│       ├── rev_svg_parser_write.cpp    # WriteToFile, SetFileName, GetFileName
│       ├── attribute_getter.cpp / clean_str.cpp / default_attributes.cpp
│       └── ...
│
└── build/                          # CMake build output

All source files are kept under 100 lines.

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Building

Prerequisites

• Qt 6 (Core, Gui, Widgets)
• C++17 compiler (g++ 9+)
• CMake 3.16+

Build

cd Assignment_1
mkdir -p build && cd build
cmake ..
make
./VectorEditor

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Acknowledgments

Developed as part of COP290 (Design Practices in Computer Science), IIT Delhi, by Prof. Smruti Ranjan Sarangi.