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<div style="float:right; clear:both; margin-left:0.5em;">__TOC__</div>
 
<div style="float:right; clear:both; margin-left:0.5em;">__TOC__</div>
 
[[Category:Widgets]]
 
[[Category:Widgets]]
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==Overview==
 
Widgets can be divided in two groups:
 
Widgets can be divided in two groups:
 
::;1. Android widgets : all [http://developer.android.com/reference/android/widget/package-summary.html native Android widgets] (under heading '''“Classes”'''). Widgets are provided by Android system.
 
::;1. Android widgets : all [http://developer.android.com/reference/android/widget/package-summary.html native Android widgets] (under heading '''“Classes”'''). Widgets are provided by Android system.
 
::;2. ginstr widgets : custom made widgets. They can be composite widgets that consist of multiple Android views or a single view with special functionality.
 
::;2. ginstr widgets : custom made widgets. They can be composite widgets that consist of multiple Android views or a single view with special functionality.
Each file in '''“layout”''' folder is called layout. Mandatory layouts as mentioned before are [[activity.xml]]and [[start.xml]]. These layouts consist of widgets. Layout can have one top element (widget) as mentioned before.  
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Each file in '''“layout”''' folder is called layout. Mandatory layouts are [[activity.xml]] and [[start.xml]]. These layouts consist of widgets. Layout can have one top element (widget) as mentioned [[Ginstr_app#Layout | here]].  
  
 
Widgets can be divided by nesting:
 
Widgets can be divided by nesting:
::;1. Container widgets (ViewGroups) : those widgets are used as containers for other widgets. The purpose is positioning assistance and layout organization. The most important are: [[LinearLayout]], [[RelativeLayout]], [[ScrollView]] (can have one child), [[FrameLayout]]. More are mentioned here.  
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::;1. Container widgets (ViewGroups) : those widgets are used as containers for other widgets. The purpose is positioning assistance and layout organization. The most important are: <code>[http://developer.android.com/reference/android/widget/LinearLayout.html LinearLayout]</code>, <code>[http://developer.android.com/reference/android/widget/RelativeLayout.html RelativeLayout]</code>, <code>[http://developer.android.com/reference/android/widget/ScrollView.html ScrollView]</code> (can have one child), <code>[http://developer.android.com/reference/android/widget/FrameLayout.html FrameLayout]</code>. More are mentioned [http://developer.android.com/reference/android/view/ViewGroup.html here].  
::;2. Action widgets : widgets that can’t nest or contain widgets within them. These widgets are used for providing functionality to app (i.e. input text, display text, call phone, send text message…), some of those are ([[TextView]], [[ImageView]], [[EditText]], [[EnEditText]], [[EnMediaAction]]…)
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::;2. Action widgets : widgets that can’t nest or contain widgets within them. These widgets are used for providing functionality to app (i.e. input text, display text, call phone, send text message…), some of those are (<code>[http://developer.android.com/reference/android/widget/TextView.html TextView]</code>, <code>[http://developer.android.com/reference/android/widget/ImageView.html ImageView]</code>, <code>[http://developer.android.com/reference/android/widget/EditText.html EditText]</code>, <code>[[GnEditText]]</code>, <code>[[GnMediaAction]]</code>…)
  
 
[[Widget Library]] contains all custom ginstr widgets that contain features not provided out of the box by Android.
 
[[Widget Library]] contains all custom ginstr widgets that contain features not provided out of the box by Android.
  
 
===Attributes===
 
===Attributes===
Attributes define how each widget behaves and what it looks like. Android widgets have attributes described for each widget for example [[TextView]], [[ImageView]], [[EditText]] (look under '''XML attributes''' and '''Inherited XML attributes'''). Each attribute has a description what its function is. This is provided for all Android widgets in Android documentation.
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Attributes define how each widget behaves and what it looks like. Android widgets have attributes described for each widget, for example <code>[http://developer.android.com/reference/android/widget/TextView.html TextView]</code>, <code>[http://developer.android.com/reference/android/widget/ImageView.html ImageView]</code>, <code>[http://developer.android.com/reference/android/widget/EditText.html EditText]</code> (look under '''XML attributes''' and '''Inherited XML attributes'''). Each attribute has a description what its function is. This is provided for all Android widgets in [http://developer.android.com/reference/android/widget/package-summary.html Android Documentation].
  
 
::Example Android widget with attributes:  
 
::Example Android widget with attributes:  
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===Mandatory attributes===
 
===Mandatory attributes===
<span style="color:#FF0000">'''!IMPORTANT!'''</span> Each widget has to have <code>android:layout_width</code>, <code>android:layout_height</code> defined. Custom widgets need custom ginstr attribute defined to work properly, check layout configuration of each widget. Attribute with asterisk (<code>*</code>) is a mandatory parameter when creating widget.
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<span style="color:#FF0000">'''!IMPORTANT!'''</span> Each widget has to have <code>android:layout_width</code>, <code>android:layout_height</code> defined. Custom widgets need custom ginstr attribute defined to work properly, check layout configuration of each [[Widget_Library | widget]]. An attribute marked with asterisk (<code>*</code>) is a mandatory parameter when creating widget.
  
 
===Widgets positioning===
 
===Widgets positioning===
One of the most important things is how to handle widget positioning within container widgets. Positioning depends on each widget within a container which depends on the container which contains it. If a widget is contained for example in [[LinearLayout]] it will not have the same positioning options as in [[RelativeLayout]]. For an introduction on the two most common containers read [[this(linear)]] and [[this(relative)]].
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One of the most important things is how to handle widget positioning within container widgets. Positioning depends on each widget within a container which depends on the container which contains it. If a widget is contained for example in <code>[http://developer.android.com/reference/android/widget/LinearLayout.html LinearLayout]</code> it will not have the same positioning options as in <code>[http://developer.android.com/reference/android/widget/RelativeLayout.html RelativeLayout]</code>.
::Example: Widget in [[RelativeLayout]] has the ability to position itself relative to other views by attribute (example under positions widget containing this attribute to right of widget with id mentioned in attribute)
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For an introduction on the two most common containers read [http://developer.android.com/reference/android/widget/LinearLayout.html this] (linear) and [http://developer.android.com/reference/android/widget/RelativeLayout.html this] (relative).
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::Example: Widget in <code>[http://developer.android.com/reference/android/widget/RelativeLayout.html RelativeLayout]</code> has the ability to position itself relative to other views by attribute (example under positions widget containing this attribute to right of widget with id mentioned in attribute)
 
::<code>android:layout_toRightOf=”@+id/idOfAnotherElementInThisContainer”</code>
 
::<code>android:layout_toRightOf=”@+id/idOfAnotherElementInThisContainer”</code>
  
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==Further Reading==
 
==Further Reading==
*[[Widget Library]]
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===[[Widget Library]]===

Revision as of 15:48, 23 June 2016

Overview

Widgets can be divided in two groups:

1. Android widgets 
all native Android widgets (under heading “Classes”). Widgets are provided by Android system.
2. ginstr widgets 
custom made widgets. They can be composite widgets that consist of multiple Android views or a single view with special functionality.

Each file in “layout” folder is called layout. Mandatory layouts are activity.xml and start.xml. These layouts consist of widgets. Layout can have one top element (widget) as mentioned here.

Widgets can be divided by nesting:

1. Container widgets (ViewGroups) 
those widgets are used as containers for other widgets. The purpose is positioning assistance and layout organization. The most important are: LinearLayout, RelativeLayout, ScrollView (can have one child), FrameLayout. More are mentioned here.
2. Action widgets 
widgets that can’t nest or contain widgets within them. These widgets are used for providing functionality to app (i.e. input text, display text, call phone, send text message…), some of those are (TextView, ImageView, EditText, GnEditText, GnMediaAction…)

Widget Library contains all custom ginstr widgets that contain features not provided out of the box by Android.

Attributes

Attributes define how each widget behaves and what it looks like. Android widgets have attributes described for each widget, for example TextView, ImageView, EditText (look under XML attributes and Inherited XML attributes). Each attribute has a description what its function is. This is provided for all Android widgets in Android Documentation.

Example Android widget with attributes:
File:attributes example.png
16.Attributes example

To use ginstr namespace attributes user has to define custom namespace in top (root) element (widget) of the layout. xmlns:ek=http://schemas.ginstr.com/ginstr. To define custom attribute following syntax is used, gn:customAttributeName=“attributeValue“

Example of a ginstr widget with attributes:
File:ginstr widget with attributes.png
17. ginstr widget with attributes

Mandatory attributes

!IMPORTANT! Each widget has to have android:layout_width, android:layout_height defined. Custom widgets need custom ginstr attribute defined to work properly, check layout configuration of each widget. An attribute marked with asterisk (*) is a mandatory parameter when creating widget.

Widgets positioning

One of the most important things is how to handle widget positioning within container widgets. Positioning depends on each widget within a container which depends on the container which contains it. If a widget is contained for example in LinearLayout it will not have the same positioning options as in RelativeLayout.

For an introduction on the two most common containers read this (linear) and this (relative).

Example: Widget in RelativeLayout has the ability to position itself relative to other views by attribute (example under positions widget containing this attribute to right of widget with id mentioned in attribute)
android:layout_toRightOf=”@+id/idOfAnotherElementInThisContainer”

Practice is needed to learn those few containers and their abilities. With combinations of containers any positioning can be achieved.

Widget data persistence

!IMPORTANT! To enable widgets that retrieve data from a user to retain data between orientation changes a unique id for widget within that layout has to be provided. Id has to be identical in both layouts (landscape/portrait). It is encouraged to use portrait only layout due to better visibility on phone Android devices.

Example:
18. ID for persistence

Further Reading

Widget Library