add: base of Layout-system

examples/layout/.editorconfig

@@ -0,0 +1,19 @@
+# EditorConfig is awesome: http://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.{cr,yml}]
+indent_style = space
+indent_size = 2
+
+[Makefile]
+indent_style = tab
+indent_size = 4

examples/layout/.gitignore

@@ -0,0 +1,13 @@
+/bin/
+/doc/
+/libs/
+/lib/
+/.crystal/
+/.shards/
+
+# Executable
+layout
+
+# Libraries don't need dependency lock
+# Dependencies will be locked in application that uses them
+/shard.lock

examples/layout/.travis.yml

@@ -0,0 +1 @@
+language: crystal

examples/layout/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2018 TamasSzekeres
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

examples/layout/Makefile

@@ -0,0 +1,15 @@
+all:
+	crystal build src/layout.cr --link-flags -L/usr/X11R6/lib/
+
+clean:
+	rm layout
+
+clear-deps:
+	rm -rf .shards
+	rm -rf lib
+	rm shard.lock
+
+install:
+	crystal deps
+
+reinstall: clear-deps install

examples/layout/README.md

@@ -0,0 +1,19 @@
+# ltk-cr/examples/layout
+
+Simple example application with using layout.
+
+## Usage
+
+Resize the window to view layout working.
+
+## Contributing
+
+1. Fork it ( https://github.com/TamasSzekeres/ltk-cr/fork )
+2. Create your feature branch (git checkout -b my-new-feature)
+3. Commit your changes (git commit -am 'Add some feature')
+4. Push to the branch (git push origin my-new-feature)
+5. Create a new Pull Request
+
+## Contributors
+
+- [TamasSzekeres](https://github.com/TamasSzekeres) Tamás Szekeres - creator, maintainer

examples/layout/shard.yml

@@ -0,0 +1,24 @@
+name: layout
+version: 0.1.0
+
+authors:
+  - Tamás Szekeres <szektam2@gmail.com>
+
+description: Simple example Window with using layout.
+
+dependencies:
+  x11:
+    path: ../../../x11-cr/.
+  cairo:
+    path: ../../../cairo-cr/.
+
+  ltk:
+    path: ../../.
+
+targets:
+  button:
+    main: src/layout.cr
+
+crystal: 0.24.1
+
+license: MIT

examples/layout/src/layout.cr

@@ -0,0 +1,43 @@
+require "ltk"
+
+module Layout
+  include Ltk
+
+  class Example
+    # Handling of clicking on the close_button.
+    def close_button_click
+      puts "close_button clicked!"
+      Application.close
+    end
+
+    def main
+      # Creating The Main Window.
+      main_win = MainWindow.new
+      main_win.title = "Ltk-Win"
+      main_win.geometry = Rect.new 10, 10, 400, 300
+      main_win.margins = Margins.new 20, 20, 20, 20
+
+      # Creating a PushButton on the Main Window.
+      one_button = PushButton.new "One", main_win
+      one_button.object_name = "one_button"
+      one_button.geometry = Rect.new 20, 20, 150, 23
+      one_button.on_click = ->close_button_click
+
+      two_button = PushButton.new "Two", main_win
+      two_button.object_name = "two_button"
+      two_button.geometry = Rect.new 20, 60, 150, 23
+      two_button.on_click = ->close_button_click
+
+      layout = HorizontalLayout.new nil
+      layout.add_widget one_button
+      layout.add_widget two_button
+
+      main_win.layout = layout
+
+      # Runs the application.
+      Application.run ARGV
+    end
+  end
+
+  Example.new.main
+end

src/ltk/base/margins.cr

@@ -1,5 +1,7 @@
 module Ltk
   struct Margins
+    ZERO = Margins.new 0, 0, 0, 0
+
     property left : Int32
     property top : Int32
     property right : Int32
@@ -62,4 +64,4 @@ module Ltk
                   (@right / divisor).round.to_i, (@bottom / divisor).round.to_i)
     end
   end
-end
+end