Post on 14-May-2015
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Hildon Desktop Widgets
Dmitry Pastushenko
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Agenda
•Hildon Desktop Home Widgets
•Widget Packaging
•Widget Declaration and Definition
•Widget API
•Hands-on
•Summary
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Hildon Desktop Widgets
4 Desktops, 3200x424 pixels total space
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Example Widget
•Calculates random numbers in 0-1000 range every second
•Changes color of generated number every 1/3 of a second
•Implements settings dialog
•Preserves battery life
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Widget Debian
Package
•
Shared Library•
/usr/lib/hildon-desktop/libwidgetexample.so
•
Desktop File•
/usr/share/applications/hildon-home/widget-example.desktop
•
Data (Resources)•
/usr/share/…
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Desktop file (widget-example.desktop)
[Desktop Entry]
Name=Widget Example
Comment=Widget Example
Type=default
X-Path=libwidgetexample.so
X-Multiple-Instances=false
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WidgetExample
Dependency
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GObject
Library
•
Cornerstone of GNOME and is used throughout GTK+, Pango, and most higher-level GNOME libraries
•
Provides transparent cross-language interoperability
•
Provides a portable object system
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WidgetExample
Class Diagram
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Widget Declaration, Part 1typedef
struct
_WidgetExample
WidgetExample;typedef
struct
_WidgetExampleClass
WidgetExampleClass;typedef
struct
_WidgetExamplePrivate
WidgetExamplePrivate;
struct
_WidgetExample
{ /* instance */ HDHomePluginItem
item; /* superclass
instance */WidgetExamplePrivate
*priv; /* private data */};
struct
_WidgetExampleClass
{ /* class */HDHomePluginItemClass
parent_class; /* superclass
*/};
GType
widget_example_get_type
(void);
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Widget Declaration, Part 2#define TYPE_WIDGET_EXAMPLE (widget_example_get_type
())#define WIDGET_EXAMPLE(obj) \(G_TYPE_CHECK_INSTANCE_CAST ((obj), TYPE_WIDGET_EXAMPLE, WidgetExample))
#define WIDGET_EXAMPLE_CLASS(klass) \(G_TYPE_CHECK_CLASS_CAST ((klass), TYPE_WIDGET_EXAMPLE, WidgetExampleClass))
#define IS_WIDGET_EXAMPLE(obj) \( G_TYPE_CHECK_INSTANCE_TYPE ((obj), TYPE_WIDGET_EXAMPLE) )
#define IS_WIDGET_EXAMPLE_CLASS(klass) \( G_TYPE_CHECK_CLASS_TYPE ((klass), TYPE_WIDGET_EXAMPLE) )
#define WIDGET_EXAMPLE_GET_CLASS(obj) \( G_TYPE_INSTANCE_GET_CLASS ((obj), TYPE_WIDGET_EXAMPLE, WidgetExampleClass) )
#define WIDGET_EXAMPLE_GET_PRIVATE(obj) \( G_TYPE_INSTANCE_GET_PRIVATE (obj, TYPE_WIDGET_EXAMPLE, WidgetExamplePrivate) )
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Widget Definition & Mandatory Methods•
HD_DEFINE_PLUGIN_MODULE (WidgetExample, widget_example, \HD_TYPE_HOME_PLUGIN_ITEM);
•
static void widget_example_class_init
(WidgetExampleClass
*class)•
Object Initialization –
override GObject::dispose, GtkWindow::realize, GtkWindow::expose_event
•
Register private data
•
static void widget_example_class_finalize
(WidgetExampleClass
*class) •
Object Destruction
•
static void widget_example_init
(WidgetExample
* applet) •
Initialize all public and private members of instance to default
values•
Create UI•
Subscribe on signals
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Call Flow
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Summary•
Follow Nokia’s UI guideline•
Should provide most crucial features•
Use semitransparent background, if applicable•
Events should be initiated on release•
Never exceed half of desktop space
•
Preserve battery life•
On current display signal •
Device inactivity state signal
•
Applet is a plug-in -
don’t forget to yield
•
Threads are allowed, but drawing should be done from main loop
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Q&A