Graphical Editor

This is a Graphical Editor written in C++ using the game engine Allegro5 as the basis for the GUI.

To Compile:

g++ source-files/ECGraphicViewImp.cpp source-files/GraphicViewMain.cpp source-files/Command.cpp source-files/ShapesModel.cpp source-files/Shape.cpp source-files/ECRealObserver.cpp source-files/MouseFunction.cpp source-files/Menu.cpp -lallegro -lallegro_font -lallegro_primitives -lallegro_main -lallegro_image -lallegro_main -lallegro_dialog -lallegro_ttf -o editor

Note: Allegro must be installed. If you are on Mac or Linux, Allegro can be installed directly. If you are on Windows, you can run Allegro5 applications through visual studio. Please refer to this video for instructions. The Allegro wiki also has some useful information about installation.

To Run:

./editor [<filename>.dat/.txt]
The above filename is optional. If included, it will attempt to load a graphical image that has been previously saved from the file. When the editor is closed, the program will save to the filename that was provided (though starting with v2.0.0, it is possible to save before program close). If no file is provided, the editor can still run, but it will be blank upon opening and will not save once closed.

The next section will go over the different program modes and how to use them. To switch modes, press the spacebar or click on the respective mode button in the menu.

Edit Mode:

This is the default mode when the editor is opened.
In this mode, the user can select and manipulate shapes.
Selecting: To select a shape, simply click within the shape's area. If there are multiple shapes in the same area, the one added most recently is selected. The selected shape will show up in blue.
Deselecting: To deselect a shape, click outside any shapes.
Deleting: To delete a shape, select it and then press the D key or press the delete button in the menu.
Moving: To move a shape, select it, and while the mouse is pressed, move the mouse to a different location. Note that when moving a shape, a light blue trace shape follows the user's mouse. It will become a 'real' shape once the user releases the mouse.
Multiple Select: By holding ctrl, multiple shapes can be selected at the same time. As with individual shapes, clicking outside of any shape will unselect all shapes. All selected shapes will be colored blue. When multiple (or individual) shapes are selected, any amount of shapes can be moved by holding the mouse down and dragging the shape to a new location, or using the arrow keys to move the selected shapes.
Grouping: When multiple shapes are selected, by pressing G or by pressing the group button in the menu, the shapes will become grouped to become a composite shape. Note that recursive grouping is possible (i.e., a composite shape can be a member of another composite shape, etc.)
Ungrouping: If only a single shape is selected, if it is a composite shape, pressing G or pressing the group button in menu will ungroup the shape. There can be multiple levels of composition.

Insert Mode:

By pressing the mouse down and dragging, a pink rectangle will be drawn onscreen showing the area in which a new shape will be inserted. A shape will be inserted when the user releases the mouse. There are four types of shapes that can be inserted:

• Unfilled Rectangle
• Filled Rectangle
• Unfilled Ellipse
• Filled Ellipse

The Unfilled Rectangle is the default shape. Pressing the "F" key once allows a filled shape to be pressed, and pressing it again goes back to unfilled mode. Pressing "G" once switches to inserting Ellipses. Pressing "G" again goes back to inserting Rectangles. Also, by pressing the corresponding shape buttons in menu, the insert shape will be changed.

The color of the insert shape can be changed by clicking the color buttons in the menu.

With v2.0.0, there are updates to the locations which a user can interact with shapes onscreen. The cursor may not be in the region of the menu when selecting a shape or when inserting a shape (either the mousedown or mouseup event associated with insertion). When moving a shape, part of the shape can be moved underneath the menu (similar to how the shape can be moved offscreen), but the mouse may not be released under the menu so there will always be a part of the shape that is accessible for the user to click. With v2.1.0, shapes must remain on the board with similar checks being made with the bounds of the window.

Undo/Redo:

The following actions can be undone/redone using the "Z" key for Undo and the "Y" key for redo or the corresponding undo and redo buttons in the menu:

• Inserting a shape
• Deleting a shape
• Moving a shape
• Grouping shapes
• Ungrouping shapes

Note that whenever a new action is completed (inserting, moving, etc.), all pending Redo operations are cleared. This is common convention for graphical editors using the command pattern.

File I/O:

The editor can be used to save and load graphical images. The editor uses a file scheme that saves all information about the shapes of a graphical image into a text file in the format of .txt or .dat.

The file scheme is as follows:

• The first line of every document is the number of shapes.
• Every line that follows gives information on an individual shape.
• The first number in each line specifies the type of shape.
  • 0 - Unfilled Rectangle
  • 1 - Unfilled Ellipse
  • 2 - Filled Rectangle
  • 3 - Filled Ellipse
  • 4 - Composite Shape
• Rectangles (both unfilled and filled): the second number is the number of sides and the next eight numbers after that are (x, y) coordinate pairs of the corners of the shape.
• Ellipses (both unfilled and filled): the following two numbers are the (x, y) coordinates of the center point, with the next two following numbers are the x radius and y radius of the ellipse.
• Composite shape: this is what a shape is called if it has been grouped. There are only two numbers on this line, the first specifying that the shape is composite, and the next number n being the number of shapes in the composite shape. Note: within the n shapes contained within each composite shape there can be nested composite shapes.
• The last number of every shape (every atomic shape, so excluding composite shapes) specifies the color of the shape.

By running the executable with a file name as the first argument, the editor will attempt to load from the file, putting all of the shapes in the model and on screen if the file can be parsed. If the file does not exist in the specified directory, an empty file will be created with the given name. The editor will appear blank apart from the menu.

After the editor is closed, every shape in the model will be saved to the file, and can be loaded at a later time.

Other Important Features

Users can save to the document they specified on the command line by pressing the S key or by clicking the save button in the menu.

Users can get help information in-application by pressing the H key or by clicking the help button in the menu.

Future Features:

• Documentation on shape scheme (Complete)
• Menu onscreen allowing users to change colors of shapes, changes modes, etc. (Complete)
• Makefile for easier compilation
• Add support for users to add onscreen text
• Allowing users to specify which file to open in the application instead of only via command line
• Detailed documentation on design patterns used
• Detailed description on how to install Allegro

Copyright Info

This project was developed as an extension of the final project for CSE 3150 at UConn in the Fall 2022 semester taught by Dr. Yufeng Wu.

Prof. Wu developed some of the starter code for this project, as well as the general guidelines (including the shape scheme). Please refer to the first commit of this repository to see the starter code he developed. This mainly included Allegro5 initialization. All other code is original.

Version 2.0.0 includes a fully functional menu, the ability to save the document (other than on application close), the addition of a help dialog, the ability to change the color of shape inserted, as well as general improvements to the code as well as improved organization and documentation.

Version 2.1.0 includes a bug fix where shapes can no longer be moved completely out of the bounds of the window. It also includes code cleanup and improvements to documentation.

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© Tyler Hinrichs 2022-2023