Homework 3: Paint

Project Description

In this assignment, you will implement a (simplified) "Paint" to learn about gui Programming with Qt. You will use object-oriented technique to implement "Paint". After this project, you are expected to learn how to develop a Qt GUI program and look for materials by yourself from the Qt API Reference.

Project Requirement

1. Create a menu bar that support the following functions: (3 pts)

   --Create a new image
   --Load a bitmap file
   --Save current image as bitmap file
   --Allow user to choose Foreground and Background color (Foreground color means the color used to draw stuff, i.e. color of the pen. Background color means the color of a new image you create. There is no need to change the background color of the existing image. The new background color only needs to be applied to the next new image you create.)
   --Support 1 level undo and redo
   --Clear the image
   --Display the toolbar

2. Create a tool bar that contains shortcuts of tools. You need to inherit from Qt::QToolBar to implement your own toolbar. Your toolbar should behave exactly like the toolbar in the sample program. (2 pts)

3. Overload the following mouse event handler to handle the corresponding mouse events: (3 pts)

   //Left click: Drawing, Right Click: popup the properties dialog of current tool
   void mousePressEvent (QMouseEvent *);
   

   //Draw the image when user dragging the mouse after Left Click
   void mouseMoveEvent (QMouseEvent *);

   //Confirm the drawing
   void mouseReleaseEvent (QMouseEvent *);

   //For terminating the drawing of polyline
   void mouseDoubleClickEvent(QMouseEvent *);

   
   

   Here are the right-click screenshots of the dialogs:

   

4. You need to implement two kinds of tools: Pen, Line. For each kind of tools, create a properties dialog that allow user to modify the properties of tool. You need to inherit from QDialog to implement your own dialog, and use QRadioButton, QButtonGroup and QSlider to implement the slider and button. (try the sample program; when you right-click on the Pen or Line Icon, its dialog will show up. You should do the same thing.) (2 pts)

To draw on an image, you need to see the API of QPainter, QPen, QBrush and QPixmap. Note the differences between drawing on a widget and an image.