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AMIGAplus Sonderheft 17 (1999)(ICP)(DE)[!].iso
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mui_numeric.doc
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TABLE OF CONTENTS
Numeric.mui/Numeric.mui
Numeric.mui/MUIA_Numeric_Default
Numeric.mui/MUIA_Numeric_Format
Numeric.mui/MUIA_Numeric_Max
Numeric.mui/MUIA_Numeric_Min
Numeric.mui/MUIA_Numeric_Reverse
Numeric.mui/MUIA_Numeric_RevLeftRight
Numeric.mui/MUIA_Numeric_RevUpDown
Numeric.mui/MUIA_Numeric_Value
Numeric.mui/MUIM_Numeric_Decrease
Numeric.mui/MUIM_Numeric_Increase
Numeric.mui/MUIM_Numeric_ScaleToValue
Numeric.mui/MUIM_Numeric_SetDefault
Numeric.mui/MUIM_Numeric_Stringify
Numeric.mui/MUIM_Numeric_ValueToScale
Numeric.mui/Numeric.mui
Numeric class is the base class for everything that
deals with the input (and display) of integer numbers.
Numeric class itself does not feature any GUI elements, it
just offers some basic attributes and methods which are
common to all types of sliders. Creating direct instances
of this class usually doesn't make any sense. Instead, use
one of the included subclasses like Slider.mui,
Numericbutton.mui or Knob.mui to select the type of gadget
you need.
Numeric class and the supplied subclasses communicate with a
set of methods. By writing subclasses which override some of
them, you can change the behaviour of all sliders to fit
your requirements. You could e.g. enhance the builtin value
formatting code which is limited to simple printf-style
strings by replacing the MUIM_Numeric_Stringify method with
something more complicated. Or you turn your sliders to
logarythmic scales by replacing MUIM_Numeric_ValueToScale
and MUIM_Numeric_ScaleToValue.
Imagine you would like a slider which doesn't only display a
users age but also makes comments depending on the current
value, e.g. "13 years (Teenie)" ... "25 years (Twen)" ...
All you have to do is to write a subclass of any of MUI's
builtin slider types which does nothing but replace
MUIM_Numeric_Stringify with your code. See the supplied
"Slidorama" demo program to see how this might work.
MUI features several different subclasses of Numeric.mui:
Slider.mui creates an ordinary slider like the ones of
previous MUI releases. Numericbutton.mui creates a
space-saving slider, only the value is shown in the user
interface as kind of a button. When the user clicks on this
button, a slider pops up to adjust the value. Knob.mui
displays a very nice designed turning wheel but also offers
popup possibilities for those who don't like turning a knob
with the mouse. "Slidorama" demo shows everything that
is available.
All slider gadgets offer configuration options and make it
easy for the user to enable things he likes and disable
things he dislikes. However, it's your choice to decide
which basic type of gadget shall be used.
If really none of the supplied subclasses of Numeric.mui
suits your requirements, you may of course write custom
classes for numeric data input. If you use Numeric.mui as
base class, you won't need to think about the basic stuff
like min and max values and formatting.
Keyboard control (TAB, cursor keys, MUIA_ControlChar) is
handled my Numeric.mui automatically, subclasses will not
have to care about it.
Numeric.mui/MUIA_Numeric_Default
NAME
MUIA_Numeric_Default -- (V11) [ISG], LONG
FUNCTION
Adjust the default value for a numeric input/display gadget.
When the object receives a MUIM_Numeric_SetDefault method,
it sets its value to the one given here.
Each type of slider can have a default value to which the
user can always return immediately by some action depending
on the implementation of the subclass. Knob.mui e.g. resets
to defaults after a double click in the knob area.
The default value can also be reached by pressing the
toggle key (usually SPACE) on an active numeric gadget.
MUIA_Numeric_Default defaults to 0.
SEE ALSO
MUIA_Numeric_Max, MUIA_Numeric_Value, MUIA_Numeric_Min,
MUIM_Numeric_SetDefault
Numeric.mui/MUIA_Numeric_Format
NAME
MUIA_Numeric_Format -- (V11) [ISG], STRPTR
FUNCTION
printf-style string to describe the format of the slider
display.
Whenever a subclass of Numeric.mui thinks its time to render
a new value, it doesn't simply write it to a string but
instead calls MUIM_Numeric_Stringify. This method of Numeric
class looks for the specified MUIA_Numeric_Format in its data
structures and fills a string with the current value.
In detail, things work like his:
- Some slider object (e.g. a knob) receives a MUIM_Draw method.
- The MUIM_Draw implementation of the knob object reads
the current value of the Numeric class and calls
MUIM_Numeric_Stringify with this valuse.
- MUIM_Numeric_Stringify of numeric class reads the current
format and sprintf()s the given value to a buffer. The
buffer is returned the caller.
- After all this stuff, the MUIM_Draw implementation
receives a nice string as result code and finally puts
it somewhere into the window.
All this method stuff might sound a bit crazy, but in fact its
quite powerful. If you write a subclass of any of MUI's slider
classes which simply replaces MUIM_Numeric_Stringify with
your own code, you can create any string you like for display
in these sliders. You might e.g. want to display a nice formatted
time string (hh:mm:ss) in a slider knob which adjusts a number
of seconds. Or you need to adjust a baudrate from a hand of
predefined values. Just overrided MUIM_Numeric_Stringify and
you have the choice how the slider value translates into
a string.
If you dont override MUIM_Numeric_Stringify, the method
reaches Numeric class which simply does a sprintf() with
the defined MUIA_Numeric_Format.
Note well: The maximum length of the result string for
MUIA_Numeric_Format is limited to 32 characters. If you
need more, you *must* override the method.
MUIA_Numeric_Format defaults to "%ld".
SEE ALSO
MUIA_Numeric_Max, MUIA_Numeric_Value, MUIA_Numeric_Min,
MUIM_Numeric_Stringify, MUIM_Numeric_StringifyValue
Numeric.mui/MUIA_Numeric_Max
NAME
MUIA_Numeric_Max -- (V11) [ISG], LONG
FUNCTION
Adjust the maximum value for a numeric input/display
gadget.
Numeric class will automatically clip its value to make
it fit between MUIA_Numeric_Min and MUI_Numeric_Max. Also,
minimum and maximum values are used for several internal
calculations such as the maximum space required to display
a numeric value.
You may change MUIA_Numeric_Min and MUIA_Numeric_Max with
SetAttrs(), but current MUI versions will *not* update
the objects and with the windows width or height if your
change causes the value display to change it's minimum
and/or maximum pixel sizes. The slider position itself
will be updated though.
MUI treats all values in numeric class as signed
longwords, so that's the limit for all tags.
MUIA_Numeric_Max defaults to 100.
NOTES
This attribute replaces the MUIA_Slider_Max tag of
previous MUI releases. For compatibility reasons,
both have the same hex value. Nevertheless, always
use MUIA_Numeric_Max in new code.
SEE ALSO
MUIA_Numeric_Min, MUIA_Numeric_Value, MUIA_Numeric_Default,
MUIM_Numeric_GetPixelSize, MUIM_Numeric_ValueToScale,
MUIM_Numeric_ScaleToValue
Numeric.mui/MUIA_Numeric_Min
NAME
MUIA_Numeric_Min -- (V11) [ISG], LONG
FUNCTION
Adjust the minimum value for a numeric input/display
gadget.
Numeric class will automatically clip its value to make
it fit between MUIA_Numeric_Min and MUI_Numeric_Max. Also,
minimum and maximum values are used for several internal
calculations such as the maximum space required to display
a numeric value.
You may change MUIA_Numeric_Min and MUIA_Numeric_Max with
SetAttrs(), but current MUI versions will *not* update
the objects and with the windows width or height if your
change causes the value display to change it's minimum
and/or maximum pixel sizes. The slider position itself
will be updated though.
MUI treats all values in numeric class as signed
longwords, so that's the limit for all tags.
MUIA_Numeric_Min defaults to 0.
NOTES
This attribute replaces the MUIA_Slider_Min tag of
previous MUI releases. For compatibility reasons,
both have the same hex value. Nevertheless, always
use MUIA_Numeric_Min in new code.
SEE ALSO
MUIA_Numeric_Max, MUIA_Numeric_Value, MUIA_Numeric_Default,
MUIM_Numeric_GetPixelSize, MUIM_Numeric_ValueToScale,
MUIM_Numeric_ScaleToValue
Numeric.mui/MUIA_Numeric_Reverse
NAME
MUIA_Numeric_Reverse -- (V11) [ISG], BOOL
FUNCTION
Reverse the display of a numeric gadget.
When set to TRUE, the MUIM_Numeric_ScaleToValue
and MUIM_Numeric_ValueToScale methods are effected
in a way that makes your gadget behave "reverse".
Its minimum numeric value will be mapped to the
maximum scale value of the display and vice versa.
MUIA_Numeric_Reverse defaults to FALSE.
NOTES
This attribute replaces the MUIA_Slider_Reverse tag
of previous MUI releases. For compatibility reasons,
both have the same hex value. Nevertheless, always
use MUIA_Numeric_Reverse in new code.
SEE ALSO
MUIA_Numeric_Max, MUIA_Numeric_Value, MUIA_Numeric_Default,
MUIM_Numeric_ValueToScale, MUIM_Numeric_ScaleToValue
Numeric.mui/MUIA_Numeric_RevLeftRight
NAME
MUIA_Numeric_RevLeftRight -- (V11) [ISG], BOOL
FUNCTION
Reverse the function of left/right keys.
Under some circumstances it might be desirable to
reverse the keyboard control for a slider gadget.
This tag might help.
MUIA_Numeric_RevLeftRight defaults to FALSE.
SEE ALSO
MUIA_Numeric_Max, MUIA_Numeric_Value, MUIA_Numeric_Default,
MUIA_Numeric_Reverse, MUIA_Numeric_RevUpDown
Numeric.mui/MUIA_Numeric_RevUpDown
NAME
MUIA_Numeric_RevUpDown -- (V11) [ISG], BOOL
FUNCTION
Reverse the function of up/down keys.
Under some circumstances it might be desirable to
reverse the keyboard control for a slider gadget.
This tag might help.
MUIA_Numeric_RevUpDown defaults to FALSE.
SEE ALSO
MUIA_Numeric_Max, MUIA_Numeric_Value, MUIA_Numeric_Default,
MUIA_Numeric_Reverse, MUIA_Numeric_RevUpDown
Numeric.mui/MUIA_Numeric_Value
NAME
MUIA_Numeric_Value -- (V11) [ISG], LONG
FUNCTION
Adjust the current value for a numeric input/display
gadget. Numeric class will automatically clip this
value to make it fit between MUIA_Numeric_Min and
MUI_Numeric_Max.
Whenever a new value is set, the object receices a
new MUIM_Draw method to get a chance to update its
display.
MUIA_Numeric_Default defaults to 0.
NOTES
This attribute replaces the MUIA_Slider_Level tag of
previous MUI releases. For compatibility reasons,
both have the same hex value. Nevertheless, always
use MUIA_Numeric_Value in new code.
SEE ALSO
MUIA_Numeric_Min, MUIA_Numeric_Max, MUIA_Numeric_Default,
MUIM_Numeric_Stringify
Numeric.mui/MUIM_Numeric_Decrease
NAME
MUIM_Numeric_Decrease (V11)
SYNOPSIS
DoMethod(obj,MUIM_Numeric_Decrease,LONG amount);
FUNCTION
Decrease the value of a numeric class object.
SEE ALSO
MUIM_Numeric_Increase, MUIA_Numeric_Value
Numeric.mui/MUIM_Numeric_Increase
NAME
MUIM_Numeric_Increase (V11)
SYNOPSIS
DoMethod(obj,MUIM_Numeric_Increase,LONG amount);
FUNCTION
Increase the value of a numeric class object.
SEE ALSO
MUIM_Numeric_Decrease, MUIA_Numeric_Value
Numeric.mui/MUIM_Numeric_ScaleToValue
NAME
MUIM_Numeric_ScaleToValue (V11)
SYNOPSIS
DoMethod(obj,MUIM_Numeric_ScaleToValue,LONG scalemin, LONG scalemax, LONG scale);
FUNCTION
This method takes the given sale values and transforms them to
something between the numeric objects min and max values.
RESULT
The transformed value.
Numeric.mui/MUIM_Numeric_SetDefault
NAME
MUIM_Numeric_SetDefault (V11)
SYNOPSIS
DoMethod(obj,MUIM_Numeric_SetDefault,);
FUNCTION
This method does nothing but reset the value to its
default. Defaults can be adjusted through
MUIA_Numeric_Default.
Only implementors of custom slider classes will need
this method. Sending it from applications doesnt make
any sense.
SEE ALSO
MUIA_Numeric_Value, MUIA_Numeric_Default
Numeric.mui/MUIM_Numeric_Stringify
NAME
MUIM_Numeric_Stringify (V11)
SYNOPSIS
DoMethod(obj,MUIM_Numeric_Stringify,LONG value);
FUNCTION
Call this method in your subclass whenever you want to
translate a value into a string. A pointer to a
string buffer is returned.
Only implementors of custom slider classes will need
this method. Sending it from applications doesnt make
any sense.
EXAMPLE
... somewhere in your Draw method ...
get(obj,MUIA_Numeric_Value,&val);
buf = DoMethod(obj,MUIM_Numeric_Stringify,val);
Text(rp,buf,strlen(buf));
SEE ALSO
MUIA_Numeric_Value, MUIA_Numeric_Format
Numeric.mui/MUIM_Numeric_ValueToScale
NAME
MUIM_Numeric_ValueToScale (V11)
SYNOPSIS
DoMethod(obj,MUIM_Numeric_ValueToScale,LONG scalemin, LONG scalemax);
FUNCTION
This method takes the current value of the numeric object and
transforms it to another scale determined by the parameters.
RESULT
The transformed value.