TRuler component description.


Author: Aleksey Denisov
Current version: 0.9
Status: Freeware, source included
Web page: www.geocities.com/CapeCanaveral/8002
E-mail: alex_den@geocities.com
Last modifyed: June 1, 1998

Properties:
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Caption: 
  This is a string there you can put for example measurement units. I recommend
  put spaces on both sides of the caption, for example: ' mm '.

CaptionAlign: 
  Controls the Caption position. 
  Possible values: caTopLeft and caBottomRight. Default-caTopLeft.

CaptionIndent1 and CaptionIndent2: 
  Can be used to adjust caption position by shifting from the side and from the
  top edge of TRuler. Negative values are possible.

EnableRepaint: 
  If set to 'True' then change of other properties will repaint entire control. 
  Set it to 'False' if you want to change several properties and use Repaint 
  method to update after making all changes.

FontRotation:
  Controls the font appearance.
  Possible values: fr0, fr90, fr180, fr270. Default-fr0 for horizontal ruler
  and fr90 for vertical.

NumberAlign:
  Controls how numbers are positioned relatively to tick marks.
  Possible values: naBottomRight, naCenter, naBottomLeft. Default-naCenter.

NumberIndent:
  Sets number indentation from the top. Can be useful with non standard fonts.

Orientation:
  Possible values: orHoriz, orVert. 

RollEnabled:
  Then this property is set to 'True', you can 'roll' the ruler with the mouse
  by dragging it.  You can control this process by onMouseDown, onMouseMove
  and onMouseUp events.

RollLimits:
  Gives you an ability to limit roll ranges. Use MinValid and MaxValid fields
  to enable or disable left or right limit and Min and Max fields to set that limit*.

StartValue:
  This field controls number appearing on the left (or on the top for vertical
  ruler) side. It uses virtual numbers*.

TickAlign:
  PossibleValues-taBottomRight (default), taTopLeft.

TickColor:
  Guess yourself.

TickSizeBig, TickSizeMiddle, TickSizeSmall:
  Controls tick size in percent of TRuler height.

UnitPresision:
  Integer fields, that sets amount of digits to show after decimal point than
  displaying numbers.

UnitPrice:
  Than displaying the integer counter is multiplied by UnitPrice value. You
  can set it to 0.5 thus getting -0.5, 0, 0.5, 1.0 numbers (do not forget to
  change UnitPrecision field). You can even set it to some negative value.

UnitSize:
  Controls number of pixels between big ticks. This is a Double type value so
  you can set it to 15.63 or whatever you want.


Take a look at my Web page for some other components. All of them will be
available soon.

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* Min, Max fields and StartValue property use 'virtual' numbering system.
That is they 'think' that ruler has zero number at the zero position and
+1, +2, : on the right; -1, -2, : on the left. Displayed number can be
different. For example, than you set UnitPrice property to 10, ruler will
show -10, 0, 10, 20, 30 values but virtual numbers will be -1, 0, 1, 2, 3.
