The Green Shoes Manual 1.1.362
Common Methods
A few methods are shared by every little element in Green Shoes. Moving, showing, hiding. Removing an element. Basic and very general things. This list encompasses those common commands.
One of the most general methods of all is the style
method (which is also covered as the style method for slots.)
Shoes.app do
stack do
# Background, text and a button:
# both are elements!
@back = background green
@text = banner "A Message for You, Rudy"
@press = button "Stop your messin about!"
# And so, both can be styled.
@text.style size: 12,
markup: fg(@text.text, red), margin: 10
@press.style width: 400
@back.style height: 10
end
end
For specific commands, see the other links to the left in the Elements section. Like if you want to pause or play a video file, check the Video section, since pausing and playing is peculiar to videos. No sense pausing a button.
Displacing an element moves it. But without changing the layout around it. This is great for subtle animations, especially if you want to reserve a place for an element while it is still animating. Like maybe a quick button shake or a slot sliding into view.
When you displace an element, it moves relative to the upper-left corner where it was placed. So, if an element is at the coordinates (20, 40) and you displace it 2 pixels left and 6 pixels on top, you end up with the coordinates (22, 46).
# Not yet available
Shoes.app do
flow :margin => 12 do
# Set up three buttons
button "One"
@two = button "Two"
button "Three"
# Bounce the second button
animate do |i|
@two.displace(0, (Math.sin(i) * 6).to_i)
end
end
end
Notice that while the second button bounces, the other two buttons stay put. If we used a normal move
in this situation, the second button would be moved out of the layout and the buttons would act as if the second button wasn't there at all. (See the move example.)
Of particular note: if you use the left
and top
methods to get the coordinates of a displaced element, you'll just get back the normal coordinates. As if there was no displacement. Displacing is just intended for quick animations!
Note: Green Shoes doesn't support displace
method.
The vertical screen size of the element in pixels. In the case of images, this is not the full size of the image. This is the height of the element as it is shown right now.
If you have a 150x150 pixel image and you set the width to 50 pixels, this method will return 50.
Also see the width method for an example and some other comments.
Hides the element, so that it can't be seen. See also show and toggle.
Gets you the pixel position of the left edge of the element.
Moves the element to a specific pixel position. The element is no longer inside the slot. So, it will not be stacked or flowed in with the other stuff in the slot. The element will float freely, now absolutely positioned instead.
Shoes.app do
# Set up three buttons
b = button "One"
@two = button "Two"
button "Three"
# Bounce the second button
animate do |i|
@two.move(33, 33 + (Math.sin(i) * 6).to_i)
end
end
The second button is moved to a specific place, allowing the third button to slide over into its place. But it will not happen until you resize the window. If you want to slide the third button without resizing the window, add flush
method.
Gets the object for this element's container. Also see the slot's contents to do the opposite: get a container's elements.
Removes the element from its slot. (In other words: throws it in the garbage.) The element will no longer be displayed.
Reveals the element, if it is hidden. See also hide and toggle.
Gives you the full set of styles applied to this element, in the form of a Hash. While methods like width
and height
and top
give you back specific pixel dimensions, using style[:width]
or style[:top]
, you can get the original setting (things like "100%" for width or "10px" for top.)
Shoes.app do
# A button which take up the whole page
@b = button "All of it",
width: width, height: height
# When clicked, show the styles
@b.click { alert(@b.style.inspect) }
end
Changes the style of an element. This could include the :width
and :height
of an element, the font :size
of some text, the :stroke
and :fill
of a shape. Or any other number of style settings.
Hides an element if it is shown. Or shows the element, if it is hidden.
Gets the pixel position of the top edge of the element.
Gets the pixel width for the full size of the element. This method always returns an exact pixel size. In the case of images, this is not the full width of the image, just the size it is shown at. See the height method for more.
Also, if you create an element with a width of 1.0 and that element is inside a stack which is 120 pixels wide, you'll get back 120
. And, if you call style[:width]
, you'll get 120
.
Shoes.app do
stack width: 120 do
@b = button "Click me", width: 1.0 do
alert "button.width = #{@b.width}\n" +
"button.style[:width] = " +
"#{@b.style[:width]}"
end
end
end
In order to set the width, you'll have to go through the style method again. So, to set the button to 150 pixels wide: @b.style(width: 150)
.
Next: Background