App.width, App.height and their meaning

[davorb]

App.width, App.height and their meaning

[wasnotrice]

+1

:height and :width should be the usable area of the window, and should not include chrome (especially since the chrome size could vary lots among platforms)

[ashbb]

:height and :width should be the usable area of the window

Totally agree. So, one more question. How to get the chrome size in SWT?

[davorb]

@ashbb I guess you could subtract the current App.width and height from the values you get out of Shell.getSize (from the way I understand it, getSize() will return the Shell's width and height).

[ashbb]

@davorb You are right. But, I think that Shell's height is y_1 in your screenshot.
We need to know the size of usable area, i.e. y_2. So, I said "How to get the chrome size (i.e. y_1 - y_2)?"
Do you know the way to get y_2 instead of y_1?

[davorb]

@ashbb I just tested it out and getSize basically works as I said. It prints out y_2.

I think the entire bugfix to this is basically:

def height
  gui_container.getSize.y
end

def width
  gui_container.getSize.x
end

EDIT: Of course you'll need to add code for setting the height and width

[PragTob]

Am I wrong or wouldn't this also fix #52 ?

I think we should wait with this fix until we can merge the changes from @ashbb (not necessarily but that would limit the merge efforts).

[wasnotrice]

This is an interesting architectural question. @davorb you are suggesting that we use backend (Swt) values to define values (i.e. height and width) that we get out of the DSL layer. This makes complete sense, since it is the backend that paints the pixels.

However, I have so far been working the opposite way: keeping all of those values in the DSL layer, and making the backend adjust to those values. The reasoning for this is that it should allow multiple backends to work more similarly, because they are all using the same Shoes values.

I envision something like (untested)

# lib/shoes/app.rb
def height=(h)
  @height = h
  @gui.height = h
end

# lib/shoes/swt/app.rb
def height=(h)
  # ensure that y_2 == h, and let the chrome size be what it will
end

Thoughts on this? @ashbb @pjfitzgibbons @PragTob @steveklabnik @alindeman

[ashbb]

Oh, two topics. :)

@davorb, @PragTob Umm,.. may be platform-dependent problem. Try out the following snippet and watch this. At least in Windows 7, shell.getSize is not y_2. :(

require 'java'
require 'swt'

module Swt::Events
  import org.eclipse.swt.events.PaintListener
end

display = Swt::Widgets::Display.new
shell = Swt::Widgets::Shell.new display, Swt::SWT::SHELL_TRIM
shell.setLayout Swt::Layout::RowLayout.new
shell.setSize 600, 500
shell.addListener Swt::SWT::Close, proc{Swt.display.dispose}

pl = Swt::Events::PaintListener.new
class << pl; self end.
instance_eval do
  define_method :paintControl do |e|
    e.gc.drawLine 0, 0, 600, 500
  end
end
shell.addPaintListener pl

b = Swt::Widgets::Button.new shell, Swt::SWT::PUSH
b.setText 'shell.getSize'
b.addSelectionListener do |e|
  pos = shell.getSize
  p [pos.x, pos.y]
end

shell.open

Swt.event_loop{Swt.display.isDisposed}

@wasnotrice I agree that we separate the DSL layer from the backend layer. But, I have a question. Why is it necessary to KEEP all of those values in the DSL layer? Isn't the following enough?

# lib/shoes/app.rb
def height
  @gui.height
end

def height=(h)
  @gui.height = h
end

# lib/shoes/swt/app.rb
def height
  # return y_2
end

def height=(h)
  # ensure that y_2 == h
end

[davorb]

@ashbb No, I'm sorry. You are of course correct.

[ashbb]

@davorb Thanks for the information. Try out the following snippet again. It it works well on all platforms, we found a solution shell.pack. :)

require 'java'
require 'swt'

module Swt::Events
  import org.eclipse.swt.events.PaintListener
end

display = Swt::Widgets::Display.new
shell = Swt::Widgets::Shell.new display, Swt::SWT::SHELL_TRIM
shell.setLayout Swt::Layout::RowLayout.new
shell.addListener Swt::SWT::Close, proc{Swt.display.dispose}

cs = Swt::Widgets::Composite.new shell, Swt::SWT::NULL
cs.setLayoutData Swt::Layout::RowData.new(600, 500)
cs.setLayout Swt::Layout::RowLayout.new
cs.set_background display.getSystemColor(Swt::SWT::COLOR_RED)

pl = Swt::Events::PaintListener.new
class << pl; self end.
instance_eval do
  define_method :paintControl do |e|
    e.gc.drawLine 0, 0, 600, 500
  end
end
cs.addPaintListener pl

b = Swt::Widgets::Button.new cs, Swt::SWT::PUSH
b.setText 'getSize'
b.addSelectionListener do |e|
  spos, cpos = shell.getSize, cs.getSize
  p "shell: #{[spos.x, spos.y]}, cs: #{[cpos.x, cpos.y]}"
end

shell.pack
shell.open

Swt.event_loop{Swt.display.isDisposed}

[davorb]

I'm getting shell: [622, 544], cs: [600, 500] in Windows 7. I think that the real size of the chrome is around ~28 pixels.

Can the difference in width really be 44 pixels? That seems like a lot.

[ashbb]

@davorb Thanks for confirmation.

Can the difference in width really be 44 pixels? That seems like a lot.

You are right. I think the difference in width really is about 38 pixels.
But no problem. Because in the above snippet, there are margin-spaces in default. We'll be able to remove the default margin-spaces (meaning: set margin-zero) in Shoes 4. ;-)

[wasnotrice]

@wasnotrice I agree that we separate the DSL layer from the backend layer. But, I have a question. Why is it necessary to KEEP all of those values in the DSL layer?

@ashbb it isn't necessary to keep values in the DSL layer. I was just commenting that, so far, that's where those values are. I think it's totally reasonable to delegate them to the GUI layer. We just have to have a good spec in place, so that other implementations give the same results. And we have to be consistent across the project :)

[ashbb]

@wasnotrice

it isn't necessary to keep values in the DSL layer.

Okay. Thanks for the reply.

@davorb Can you close this thread? Or need more discussion?

[davorb]

Wait... so what did we actually decide? To keep it the way it is or to change it?