Liqbase library overview - Revision history

amigadave: wikify slightly, mark as outof date

2011-02-08T12:59:02Z

wikify slightly, mark as outof date

← Older revision		Revision as of 12:59, 8 February 2011
Line 1:		Line 1:
-	=liqbase :: the core library=	+	{{out of date}}
		+
		+	==liqbase :: the core library==

	'''Note, this document describes a library which is not currently available, however its precursor [[liqbase]] is available for download:'''		'''Note, this document describes a library which is not currently available, however its precursor [[liqbase]] is available for download:'''
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	it will be expanded upon over the coming days.		it will be expanded upon over the coming days.

-	==~~Rational~~==	+	===Rationale===

	liqbase was born of frustration.		liqbase was born of frustration.
Line 25:		Line 27:
	At present it is very specifically focused upon the Nokia internet tablet computers though it is compilable and usable within x86 linux as well.		At present it is very specifically focused upon the Nokia internet tablet computers though it is compilable and usable within x86 linux as well.

-	==Why not GTK+ or Qt?==	+	===Why not GTK+ or Qt?===

	I looked carefully at GTK+ when I first got my tablet and would have been happy it if it had the required performance, it has (semi) sane construction methods and an expansive library of controls and utility functions.		I looked carefully at GTK+ when I first got my tablet and would have been happy it if it had the required performance, it has (semi) sane construction methods and an expansive library of controls and utility functions.
Line 33:		Line 35:
	I wanted to do things which I took for granted on my old PDA and have done for years in Visual Basic and found the existing toolkits lacking.		I wanted to do things which I took for granted on my old PDA and have done for years in Visual Basic and found the existing toolkits lacking.

-	==Dependencies==	+	===Dependencies===

	liqbase makes use of the following libraries:		liqbase makes use of the following libraries:
Line 47:		Line 49:
	*sqlite3 for the database manipulation		*sqlite3 for the database manipulation

-	graphics are rendered using the XV library using the YUV video format.	+	graphics are rendered using the XV library using the YUV video format. This is a lower bandwidth video mode which has full resolution Luma, but half resolution Chroma.
-	This is a lower bandwidth video mode which has full resolution Luma, but half resolution Chroma.	+

-		+	===Base Classes===
-	==Base Classes==	+

	It is being constructed around a core set of interrelated classes		It is being constructed around a core set of interrelated classes
Line 61:		Line 61:
	*liqsketch a dynamic sketch built up from various strokes and points		*liqsketch a dynamic sketch built up from various strokes and points
	*liqcliprect a physical rectangle within an image with direct drawing routines		*liqcliprect a physical rectangle within an image with direct drawing routines
-

	Beyond the core there is a second layer of classes dealing with structured layout and rendering		Beyond the core there is a second layer of classes dealing with structured layout and rendering
Line 67:		Line 66:
	*liqcell a single unit capable of holding or representing physical or meta data		*liqcell a single unit capable of holding or representing physical or meta data
	*liqgraph a special resolution independent graphics interface which a cell uses		*liqgraph a special resolution independent graphics interface which a cell uses
-

	With these classes I will be able to construct the applications started inside liqbase.		With these classes I will be able to construct the applications started inside liqbase.
-

	The classes outlined here existed in some form or other in the old liqbase and I have not yet documented the descendants of the cell class which sit together to form the UI itself.		The classes outlined here existed in some form or other in the old liqbase and I have not yet documented the descendants of the cell class which sit together to form the UI itself.

-	==system class structure==	+	===system class structure===

	The system classes created in liqbase follow the same object pattern and contain the following default standard methods:		The system classes created in liqbase follow the same object pattern and contain the following default standard methods:
Line 106:		Line 103:
	There is no concept of inheritance at this level, however once you have instances of cell classes (described in detail below) they follow generic inheritance rules and can expand.		There is no concept of inheritance at this level, however once you have instances of cell classes (described in detail below) they follow generic inheritance rules and can expand.

-		+	===Example cell lifespan===
-	==Example cell lifespan==	+

	A usual cycle goes something like this		A usual cycle goes something like this
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	</source>		</source>

-	==Cell inheritance==	+	===Cell inheritance===

	The cell class provides a basic unit which everything is built up from. When used in a visual context, it represents a rectangular area on the screen. A cell can also be used as a simple property holding information intended for its parent. Each cell can hold references to a font, an image and a sketch or even another cell. It can be inherited from other cells which expand its utility and purpose.		The cell class provides a basic unit which everything is built up from. When used in a visual context, it represents a rectangular area on the screen. A cell can also be used as a simple property holding information intended for its parent. Each cell can hold references to a font, an image and a sketch or even another cell. It can be inherited from other cells which expand its utility and purpose.

-	==Dynamic scaling==	+	===Dynamic scaling===

	liqbase is designed to operate in a truly resolution independent manner, after designing a widget according to specifications, it does not matter whether it is run on a lower or higher resolution display as the content will render correctly.		liqbase is designed to operate in a truly resolution independent manner, after designing a widget according to specifications, it does not matter whether it is run on a lower or higher resolution display as the content will render correctly.
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	I have taken special care ensuring the font class operates as expected within a dynamic resolution independent environment. At design time, the operator configures a form to certain dimensions (at 225dpi) and configures font sizes and positions relative to this. The fonts make use of extensive dynamic caching to both improve loading speed and to ensure that the correct glyph is displayed at the correct size as required. The slight drawback with this approach is that at different scales there is some very slight variation in the exact final font size due to integer only glyph widths.		I have taken special care ensuring the font class operates as expected within a dynamic resolution independent environment. At design time, the operator configures a form to certain dimensions (at 225dpi) and configures font sizes and positions relative to this. The fonts make use of extensive dynamic caching to both improve loading speed and to ensure that the correct glyph is displayed at the correct size as required. The slight drawback with this approach is that at different scales there is some very slight variation in the exact final font size due to integer only glyph widths.

-	At runtime, the entire screen is situated within the available boundary and rendered accordingly.	+	At runtime, the entire screen is situated within the available boundary and rendered accordingly. A landscape layout will run correctly in portrait mode, however it will be displayed at a reduced size to maintain its aspect ratio.
-	A landscape layout will run correctly in portrait mode, however it will be displayed at a reduced size to maintain its aspect ratio.	+
-		+

-	==Event handlers==	+	===Event handlers===

	You can assign event handlers to any cell in liqbase and have a routine called when the event is required.		You can assign event handlers to any cell in liqbase and have a routine called when the event is required.
	New events can be dynamically created and utilized as required.		New events can be dynamically created and utilized as required.

-	===Linking handler to cell===	+	====Linking handler to cell====

	<source lang="c">		<source lang="c">
Line 158:		Line 152:
	</source>		</source>

-	===Handler Code===	+	====Handler Code====

	<source lang="c">		<source lang="c">
Line 169:		Line 163:
	</source>		</source>

-	===Using a handler===	+	====Using a handler====

	<source lang="c">		<source lang="c">

amigadave: wikify, categorize

2010-05-11T12:40:01Z

wikify, categorize

← Older revision		Revision as of 12:40, 11 May 2010
Line 25:		Line 25:
	At present it is very specifically focused upon the Nokia internet tablet computers though it is compilable and usable within x86 linux as well.		At present it is very specifically focused upon the Nokia internet tablet computers though it is compilable and usable within x86 linux as well.

-	==Why not GTK or QT?==	+	==Why not GTK+ or Qt?==

-	I looked carefully at GTK when I first got my tablet and would have been happy it if it had the required performance, it has (semi) sane construction methods and an expansive library of controls and utility functions.	+	I looked carefully at GTK+ when I first got my tablet and would have been happy it if it had the required performance, it has (semi) sane construction methods and an expansive library of controls and utility functions.

-	However on the tablet graphical performance was so poor that anything I attempted felt slow and applications crawled along.	+	However on the tablet graphical performance was so poor that anything I attempted felt slow and applications crawled along. Qt had its own problems and still is not a viable option on the devices.
-	QT had its own problems and still is not a viable option on the devices.	+

	I wanted to do things which I took for granted on my old PDA and have done for years in Visual Basic and found the existing toolkits lacking.		I wanted to do things which I took for granted on my old PDA and have done for years in Visual Basic and found the existing toolkits lacking.
Line 78:		Line 77:

	The system classes created in liqbase follow the same object pattern and contain the following default standard methods:		The system classes created in liqbase follow the same object pattern and contain the following default standard methods:
-	<~~PRE~~>	+	<source lang="c">
	class *class_new()		class *class_new()
	{		{
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	// call _release on all members of this class		// call _release on all members of this class
	}		}
-	</~~PRE~~>	+	</source>

	User classes and instances built from cells do not require this interface.		User classes and instances built from cells do not require this interface.
Line 106:		Line 105:
	The reference counting is held as a private member inside the instance itself.		The reference counting is held as a private member inside the instance itself.
	There is no concept of inheritance at this level, however once you have instances of cell classes (described in detail below) they follow generic inheritance rules and can expand.		There is no concept of inheritance at this level, however once you have instances of cell classes (described in detail below) they follow generic inheritance rules and can expand.
-


Line 113:		Line 111:
	A usual cycle goes something like this		A usual cycle goes something like this

-	<~~PRE~~>	+	<source lang="c">
-		+
	void hello_world()		void hello_world()
	{		{
Line 134:		Line 131:
	liqcell_release(myform);		liqcell_release(myform);
	}		}
-	</~~PRE~~>	+	</source>

	==Cell inheritance==		==Cell inheritance==

-	The cell class provides a basic unit which everything is built up from.	+	The cell class provides a basic unit which everything is built up from. When used in a visual context, it represents a rectangular area on the screen. A cell can also be used as a simple property holding information intended for its parent. Each cell can hold references to a font, an image and a sketch or even another cell. It can be inherited from other cells which expand its utility and purpose.
-	When used in a visual context, it represents a rectangular area on the screen.	+
-	A cell can also be used as a simple property holding information intended for its parent.	+
-	Each cell can hold references to a font, an image and a sketch or even another cell.	+
-	It can be inherited from other cells which expand its utility and purpose.	+

	==Dynamic scaling==		==Dynamic scaling==
Line 148:		Line 141:
	liqbase is designed to operate in a truly resolution independent manner, after designing a widget according to specifications, it does not matter whether it is run on a lower or higher resolution display as the content will render correctly.		liqbase is designed to operate in a truly resolution independent manner, after designing a widget according to specifications, it does not matter whether it is run on a lower or higher resolution display as the content will render correctly.

-	I have taken special care ensuring the font class operates as expected within a dynamic resolution independent environment.	+	I have taken special care ensuring the font class operates as expected within a dynamic resolution independent environment. At design time, the operator configures a form to certain dimensions (at 225dpi) and configures font sizes and positions relative to this. The fonts make use of extensive dynamic caching to both improve loading speed and to ensure that the correct glyph is displayed at the correct size as required. The slight drawback with this approach is that at different scales there is some very slight variation in the exact final font size due to integer only glyph widths.
-	At design time, the operator configures a form to certain dimensions (at 225dpi) and configures font sizes and positions relative to this.	+
-	The fonts make use of extensive dynamic caching to both improve loading speed and to ensure that the correct glyph is displayed at the correct size as required. The slight drawback with this approach is that at different scales there is some very slight variation in the exact final font size due to integer only glyph widths.	+

	At runtime, the entire screen is situated within the available boundary and rendered accordingly.		At runtime, the entire screen is situated within the available boundary and rendered accordingly.
Line 162:		Line 153:

	===Linking handler to cell===		===Linking handler to cell===
-	<~~PRE~~>	+
		+	<source lang="c">
	*vcell_handleradd(self, "paint", world_paint);		*vcell_handleradd(self, "paint", world_paint);
-	</~~PRE~~>	+	</source>

	===Handler Code===		===Handler Code===
-	<~~PRE~~>	+
		+	<source lang="c">
	static int world_paint(vcell self, vcellpainteventargs args)		static int world_paint(vcell self, vcellpainteventargs args)
	{		{
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	return 1;		return 1;
	}		}
-	</~~PRE~~>	+	</source>

	===Using a handler===		===Using a handler===
-	<~~PRE~~>	+
		+	<source lang="c">
	vcell_handlerrun(self,"paint",&paintargs);		vcell_handlerrun(self,"paint",&paintargs);
-	</~~PRE~~>	+	</source>
		+
		+	[[Category:Software]]
		+	[[Category:Documentation]]

lcuk at 10:22, 29 January 2009

2009-01-29T10:22:57Z

← Older revision		Revision as of 10:22, 29 January 2009
Line 75:		Line 75:
	The classes outlined here existed in some form or other in the old liqbase and I have not yet documented the descendants of the cell class which sit together to form the UI itself.		The classes outlined here existed in some form or other in the old liqbase and I have not yet documented the descendants of the cell class which sit together to form the UI itself.

-	==class structure==	+	==system class structure==

-		+	The system classes created in liqbase follow the same object pattern and contain the following default standard methods:
-	~~Most~~ classes created in liqbase follow the same object pattern and contain the following default standard methods:	+
	<PRE>		<PRE>
	class *class_new()		class *class_new()
Line 102:		Line 101:
	}		}
	</PRE>		</PRE>
		+
		+	User classes and instances built from cells do not require this interface.
		+
	The reference counting is held as a private member inside the instance itself.		The reference counting is held as a private member inside the instance itself.
-
	There is no concept of inheritance at this level, however once you have instances of cell classes (described in detail below) they follow generic inheritance rules and can expand.		There is no concept of inheritance at this level, however once you have instances of cell classes (described in detail below) they follow generic inheritance rules and can expand.
-

lcuk at 13:45, 28 January 2009

2009-01-28T13:45:12Z

← Older revision		Revision as of 13:45, 28 January 2009
Line 154:		Line 154:
	At runtime, the entire screen is situated within the available boundary and rendered accordingly.		At runtime, the entire screen is situated within the available boundary and rendered accordingly.
	A landscape layout will run correctly in portrait mode, however it will be displayed at a reduced size to maintain its aspect ratio.		A landscape layout will run correctly in portrait mode, however it will be displayed at a reduced size to maintain its aspect ratio.
		+
		+
		+	==Event handlers==
		+
		+	You can assign event handlers to any cell in liqbase and have a routine called when the event is required.
		+	New events can be dynamically created and utilized as required.
		+
		+	===Linking handler to cell===
		+	<PRE>
		+	*vcell_handleradd(self, "paint", world_paint);
		+	</PRE>
		+
		+	===Handler Code===
		+	<PRE>
		+	static int world_paint(vcell self, vcellpainteventargs args)
		+	{
		+	//liqapp_log("painting...");
		+	// tell the subsystem this event has been handled (returning 0 will cause the chain to continue)
		+	return 1;
		+	}
		+	</PRE>
		+
		+	===Using a handler===
		+	<PRE>
		+	vcell_handlerrun(self,"paint",&paintargs);
		+	</PRE>

lcuk at 11:41, 28 January 2009

2009-01-28T11:41:14Z

← Older revision		Revision as of 11:41, 28 January 2009
Line 135:		Line 135:
	}		}
	</PRE>		</PRE>
		+
		+	==Cell inheritance==
		+
		+	The cell class provides a basic unit which everything is built up from.
		+	When used in a visual context, it represents a rectangular area on the screen.
		+	A cell can also be used as a simple property holding information intended for its parent.
		+	Each cell can hold references to a font, an image and a sketch or even another cell.
		+	It can be inherited from other cells which expand its utility and purpose.
		+
		+	==Dynamic scaling==
		+
		+	liqbase is designed to operate in a truly resolution independent manner, after designing a widget according to specifications, it does not matter whether it is run on a lower or higher resolution display as the content will render correctly.
		+
		+	I have taken special care ensuring the font class operates as expected within a dynamic resolution independent environment.
		+	At design time, the operator configures a form to certain dimensions (at 225dpi) and configures font sizes and positions relative to this.
		+	The fonts make use of extensive dynamic caching to both improve loading speed and to ensure that the correct glyph is displayed at the correct size as required. The slight drawback with this approach is that at different scales there is some very slight variation in the exact final font size due to integer only glyph widths.
		+
		+	At runtime, the entire screen is situated within the available boundary and rendered accordingly.
		+	A landscape layout will run correctly in portrait mode, however it will be displayed at a reduced size to maintain its aspect ratio.

lcuk at 11:25, 28 January 2009

2009-01-28T11:25:53Z

← Older revision		Revision as of 11:25, 28 January 2009
Line 44:		Line 44:
	*xsp for the pressure sensitive mouse input		*xsp for the pressure sensitive mouse input
	*ttflib ttf font handling		*ttflib ttf font handling
-	*libpng	+	*libpng for reading and writing image data
	*libjpeg		*libjpeg
		+	*sqlite3 for the database manipulation

	graphics are rendered using the XV library using the YUV video format.		graphics are rendered using the XV library using the YUV video format.

lcuk at 21:00, 27 January 2009

2009-01-27T21:00:56Z

← Older revision		Revision as of 21:00, 27 January 2009
Line 51:		Line 51:


-	==~~core classes~~==	+	==Base Classes==

	It is being constructed around a core set of interrelated classes		It is being constructed around a core set of interrelated classes

lcuk at 21:00, 27 January 2009

2009-01-27T21:00:15Z

← Older revision		Revision as of 21:00, 27 January 2009
Line 68:		Line 68:
	*liqgraph a special resolution independent graphics interface which a cell uses		*liqgraph a special resolution independent graphics interface which a cell uses

-	~~With these classes I will be able to construct the applications started inside liqbase~~

		+	With these classes I will be able to construct the applications started inside liqbase.
		+
		+
		+	The classes outlined here existed in some form or other in the old liqbase and I have not yet documented the descendants of the cell class which sit together to form the UI itself.

	==class structure==		==class structure==

lcuk at 20:52, 27 January 2009

2009-01-27T20:52:15Z

← Older revision		Revision as of 20:52, 27 January 2009
Line 33:		Line 33:

	I wanted to do things which I took for granted on my old PDA and have done for years in Visual Basic and found the existing toolkits lacking.		I wanted to do things which I took for granted on my old PDA and have done for years in Visual Basic and found the existing toolkits lacking.
		+
	==Dependencies==		==Dependencies==

Line 106:		Line 107:
	==Example cell lifespan==		==Example cell lifespan==

-	A usual cycle goes like this	+	A usual cycle goes something like this

	<PRE>		<PRE>

lcuk at 20:51, 27 January 2009

2009-01-27T20:51:30Z

← Older revision		Revision as of 20:51, 27 January 2009
Line 23:		Line 23:
	It has been written in C for both speed and expandability.		It has been written in C for both speed and expandability.

-	At present it is very specifically focused upon the Nokia internet tablet computers ~~running~~ linux.	+	At present it is very specifically focused upon the Nokia internet tablet computers though it is compilable and usable within x86 linux as well.

	==Why not GTK or QT?==		==Why not GTK or QT?==