paweld/lazarus
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/lazarus/lazarus.git synced 2025-08-14 09:59:20 +02:00
Code Issues Packages Projects Releases Wiki Activity

Docs: LCL/arrow. Adds content for overridden TArrow.Paint method.

Browse Source
This commit is contained in:
dsiders 2022-08-18 20:41:52 +01:00
parent e0fb044351
commit bcffeb9e1e
1 changed files with 54 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
docs/xml/lcl/arrow.xml
View File

@ -96,11 +96,61 @@ The following components are added to the Lazarus IDE component palette:
<seealso/> <seealso/>
</element> </element>
<element name="TArrow.GetControlClassDefaultSize" link="#lcl.controls.TControl.GetControlClassDefaultSize"/> <element name="TArrow.GetControlClassDefaultSize" link="#lcl.controls.TControl.GetControlClassDefaultSize"/>
<element name="TArrow.Paint" link="#lcl.controls.TCustomControl.Paint">
<short/> <element name="TArrow.Paint">
<descr/> <short>
<seealso/> Implements the paint handler used to draw the control.
</short>
<descr>
<p>
<var>Paint</var> is an overridden method in <var>TArrow</var>. It extends the
inherited to method to perform actions needed to draw the shape and an
optional shadow.
</p>
<p>
Paint calculates the internal TPoint instances needed for the triangular
shape using the values in ArrowType and ArrowPointerAngle. It configures the
control Canvas with the values in Color, ArrowColor, ShadowColor, and
AntiAliasingMode.
</p>
<p>
Methods in Canvas are called to render the shape. FillRect is called to draw
the background for the control Polygon is called to draw both the shadow and
the arrow on the control. The MoveTo and LineTo methods are used to draw the
lines needed for an unfilled shadow.
</p>
<p>
Use Color to set the background color for the client area in the shape.
</p>
<p>
Use ArrowColor to set the color for the Pen and Brush used to draw the arrow
shape.
</p>
<p>
Use ShadowType and ShadowColor to draw a shadow for the shape with the
desired color and drawing style.
</p>
<p>
Paint calls the inherited method prior to exit to signal the OnPaint event
handler (when assigned).
</p>
<p>
Paint is called when the WM_PAINT window message is handled for the control.
</p>
</descr>
<seealso>
<link id="TArrow.ShadowType"/>
<link id="TArrow.ShadowColor"/>
<link id="TArrow.ArrowType"/>
<link id="TArrow.ArrowColor"/>
<link id="TArrow.ArrowPointerAngle"/>
<link id="#lcl.industrialbase.TIndustrialBase.AntiAliasingMode">TIndustrialBase.AntiAliasingMode</link>
<link id="#lcl.controls.TGraphicControl.Canvas">TGraphicControl.Canvas</link>
<link id="#lcl.controls.TGraphicControl.Paint">TGraphicControl.Paint</link>
<link id="#lcl.controls.TGraphicControl.OnPaint">TGraphicControl.OnPaint</link>
</seealso>
</element> </element>
<!-- constructor Visibility: public --> <!-- constructor Visibility: public -->
<element name="TArrow.Create"> <element name="TArrow.Create">
<short>Constructor for the class instance.</short> <short>Constructor for the class instance.</short>