W1502 Object Attributes
Prerequisites[edit]
Research[edit]
- Predefined color names may be found here: CSS Color Keywords, or, colors may be created by their RGB values using the constructor:
Color(red:UInt8, green:UInt8, blue:UInt8)
Experiment[edit]
Enter into the Sources/IgisShellD directory of the W1501 experience.
cd ~/Experiences/W1501/Sources/IgisShellD
Open main.swift in emacs.
emacs main.swift
Find the function within the Painter object named "setup". Edit the contents as follows to specify the fill color of the rectangle:
func setup(canvas:Canvas) {
let rect = Rect(topLeft:Point(x:100, y:50), size:Size(width:200, height:300))
let rectangle = Rectangle(rect:rect)
let fillStyle = FillStyle(color:Color(.blue))
canvas.render(fillStyle)
canvas.render(rectangle)
}
Remember to save the file, then suspend emacs.
 |
Run the program and refresh the browser page. |
 |
Stop the running program. |
Let's stroke the rectangle in green instead of filling it. Interrupt the running program and then resume emacs and edit the setup function so it appears as follows:
func setup(canvas:Canvas) {
let rect = Rect(topLeft:Point(x:100, y:50), size:Size(width:200, height:300))
let rectangle = Rectangle(rect:rect, fillMode:.stroke)
let strokeStyle = StrokeStyle(color:Color(.green))
canvas.render(strokeStyle)
canvas.render(rectangle)
}
Remember to save the file, then suspend emacs.
|
Run the program and refresh the browser page. |
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Stop the running program. |
Let's thicken the stroke line. Interrupt the running program and then resume emacs and add the following lines so that the entire function appears as:
func setup(canvas:Canvas) {
let rect = Rect(topLeft:Point(x:100, y:50), size:Size(width:200, height:300))
let rectangle = Rectangle(rect:rect, fillMode:.stroke)
let strokeStyle = StrokeStyle(color:Color(.green))
let lineWidth = LineWidth(width:5)
canvas.render(strokeStyle)
canvas.render(lineWidth)
canvas.render(rectangle)
}
Remember to save the file, then suspend emacs.
|
Run the program and refresh the browser page. |
|
Stop the running program. |
Finally, let's both stroke and fill simultaneously. Interrupt the running program and then resume emacs and add the following lines so that the entire function appears as:
func setup(canvas:Canvas) {
let rect = Rect(topLeft:Point(x:100, y:50), size:Size(width:200, height:300))
let rectangle = Rectangle(rect:rect, fillMode:.fillAndStroke)
let fillStyle = FillStyle(color:Color(.green))
let strokeStyle = StrokeStyle(color:Color(.blue))
let lineWidth = LineWidth(width:5)
canvas.render(fillStyle)
canvas.render(strokeStyle)
canvas.render(lineWidth)
canvas.render(rectangle)
}
Remember to save the file, then suspend emacs.
|
Run the program and refresh the browser page. |
|
Stop the running program. |
Exercises[edit]
Continuing your previous project of (at least) three skyscrapers:
- Color the sky and ground
- Color the body of each skyscraper in a different color
- Color various aspects of your skyscraper (e.g. windows, doors) in different colors
When done, you must have at least seven different colors on your canvas.
