Complete the basic material on traitsui.

Author: prabhuramachandran

slides/03_traitsui.md

@@ -5,7 +5,7 @@ jupyter:
       extension: .md
       format_name: markdown
       format_version: '1.3'
-      jupytext_version: 1.13.7
+      jupytext_version: 1.14.0
   kernelspec:
     display_name: Python 3 (ipykernel)
     language: python
@@ -39,7 +39,7 @@ jupyter:
 
 - Just declare what needs to be done
 - Do not need to write a lot of code
-- Embed 2D plots with `chaco`
+- Embed 2D plots with `matplotlib` or `chaco`
 - Embed 3D plots with `mayavi`
 - Build rich scientific dialogs
 
@@ -82,12 +82,13 @@ jupyter:
 <!-- #endregion -->
 
 ```python
-from traits.api import HasStrictTraits, Int, Str, Enum
+from traits.api import HasStrictTraits, Int, Str, Enum, Bool
 
 class Person(HasStrictTraits):
-    name = Str()
-    age = Int()
+    name = Str
+    age = Int
     handedness = Enum('left', 'right')
+    drinks = Bool(False)
 
 ```
 
@@ -111,7 +112,8 @@ from traitsui.api import Item, View
 view1 = View(
     Item(name='name', style='readonly'),
     Item(name='age'),
-    Item(name=handedness', visible_when='age > 10'),
+    Item(name='handedness'),
+    Item(name='drinks', visible_when='age >= 18'),
 )
 ```
 
@@ -156,16 +158,16 @@ p.edit_traits(view=view1)
 from traitsui.api import Group
 
 class Person(HasStrictTraits):
-    name = Str()
-    age = Int()
-    gender = Enum('female', 'male', 'other')
+    name = Str
+    age = Int
+    handedness = Enum('left', 'right')
 
     traits_view = View(
       Group(
         Item(name='name'),
         Item(name='age'),
-        Item(name='gender'),
-        label='Personnel profile',
+        Item(name='handedness'),
+        label='Person profile',
         show_border=True
       )
     )
@@ -184,10 +186,10 @@ p.edit_traits()
 ## View attributes
 
 - `dock`: `{'fixed', 'horizontal', 'vertical', 'tabbed'}`
-- `height`/`width`
+- `height`/`width`: int
 - `icon`/`image`
-- `resizable`
-- `scrollable`
+- `resizable`: bool
+- `scrollable`: bool
 - `title`: name of the window
 - `buttons`
 - `key_bindings`
@@ -203,16 +205,17 @@ p.edit_traits()
 from traitsui.api import CancelButton, OKButton
 
 class Person(HasStrictTraits):
-    name = Str()
-    age = Int()
-    gender = Enum('female', 'male', 'other')
+    name = Str
+    age = Int
+    likes_queso = Bool
+    handedness = Enum('left', 'right')
 
     traits_view = View(
       Group(
         Item(name='name'),
         Item(name='age'),
-        Item(name='gender'),
-        label='Personnel profile',
+        Item(name='handedness'),
+        label='Person profile',
         show_border=True,
       ),
       buttons=[OKButton, CancelButton]
@@ -225,6 +228,92 @@ p = Person(name='Worf', age=20)
 p.edit_traits()
 ```
 
+<!-- #region slideshow={"slide_type": "slide"} -->
+## Specifying an editor
+
+- We illustrate the powerful `InstanceEditor` here
+- Consider the following
+
+<!-- #endregion -->
+
+```python
+from traits.api import Instance
+
+class Person(HasStrictTraits):
+    name = Str
+    age = Int
+    handedness = Enum('left', 'right')
+    bff = Instance('Person')  # Notice the quotes.
+
+    traits_view = View(
+      Group(
+        Item(name='name'),
+        Item(name='age'),
+        Item(name='handedness'),
+        Item(name='bff', style='custom'),
+        label='Person profile',
+      )
+    )
+```
+
+```python
+frodo = Person(name='Frodo', age=30)
+sam = Person(name='Sam', age=29, bff=frodo)
+```
+```python
+sam.edit_traits()
+```
+
+<!-- #region slideshow={"slide_type": "slide"} -->
+## Discussion
+
+- Note the embedding
+- Implicitly uses an InstanceEditor
+- Can configure the view it uses if needed
+
+<!-- #endregion -->
+
+```python
+from traitsui.api import InstanceEditor
+
+bff_view = View(Group(
+        Item(name='name'),
+        Item(name='age'),
+        Item(name='handedness'),
+        label='BFF',
+        )
+    )
+```
+
+```python slideshow={"slide_type": "slide"}
+class Person(HasStrictTraits):
+    name = Str
+    age = Int
+    handedness = Enum('left', 'right')
+    bff = Instance('Person')
+
+    traits_view = View(
+      Group(
+        Item(name='name'),
+        Item(name='age'),
+        Item(name='handedness'),
+        Item(name='bff', style='custom', show_label=False,
+             editor=InstanceEditor(view=bff_view)),
+        label='Person profile',
+      )
+    )
+```
+
+
+```python
+frodo = Person(name='Frodo', age=30)
+sam = Person(name='Sam', age=29, bff=frodo)
+```
+```python
+sam.edit_traits()
+```
+
+
 
 <!-- #region slideshow={"slide_type": "slide"} -->
 ## Toolkit selection