Class de.unikl.AWTNode.ConnectionLinePoints
All Packages Class Hierarchy This Package Previous Next Index
Class de.unikl.AWTNode.ConnectionLinePoints
java.lang.Object
|
+----java.awt.Component
|
+----de.unikl.AWTNode.ConnectionLinePoints
- public class ConnectionLinePoints
- extends Component
The class ConnectionLinePoints is a lightweight component.
The basic idea is, that this class stores only lines, given
with a StartPoint (x1,y1) and an endpoint (x2,y2)
Important: This class uses the graphics-context of its container
If you call the paint method of this class, all the lines
are painted in the parents graphic context. Thus this
lightweigth component have to know ist parent.
You can set the parent of the Component with the method:
setParent(Component parent)
To get a higher performance between the steps:
1. hide the actual Objekt
2. fill the Objekt with new lines
3. paint these lines
there is a possibility to put the "invalid" lines in a
Buffer. If there are invalid lines in the buffer the
paint method of this component first hide these
invalid lines, and then it paints the new lines.
For what is this class good for?
As an example you can store all the lines in it, which you need
if you implement a tree-view. In a tree-view you have lines
from each parent-Node to its son-nodes.
internal implementation:
The lines are stored in a vector structure.
-
addElement(Point, Point)
- adds a new Line to the Object
Note:
Lines are stored in the coordinate space of the Container,
or Component to which this Object belongs to.
-
elementAt(int)
- return the LinePoints Object at the given index position
-
getLineCount()
- returns the number of currentLines-Elements in this Object
-
isPainted()
- returns whether the Object is painted in the paint method
or not.
-
paint(Graphics)
- Paints the object.
-
resetLines()
- Clears the currentLine variable, and append the current lines
to the oldLines object.
-
setPainted(boolean)
- This method sets the painted flag for the Object.
-
setParent(Component)
- This Method is important if the Object should draw its
Lines in the parents graphic context.
-
toString()
-
addElement
public void addElement(Point a,
Point b)
- adds a new Line to the Object
Note:
Lines are stored in the coordinate space of the Container,
or Component to which this Object belongs to.
This is important if you construct the graphics context
in which the lines should draw themselves
- Parameters:
- a - the Startpoint of the line (in parents coordiante space)
- b - the EndPoint of the line (in parents coordiante space)
getLineCount
public int getLineCount()
- returns the number of currentLines-Elements in this Object
elementAt
public LinePoints elementAt(int pos)
- return the LinePoints Object at the given index position
resetLines
public void resetLines()
- Clears the currentLine variable, and append the current lines
to the oldLines object.
isPainted
public boolean isPainted()
- returns whether the Object is painted in the paint method
or not.
setParent
public void setParent(Component parent)
- This Method is important if the Object should draw its
Lines in the parents graphic context.
You must specify a parent or the Object cannot get
the graphic context and cannot be drawn.
setPainted
public void setPainted(boolean lpaint)
- This method sets the painted flag for the Object.
paint
public void paint(Graphics g)
- Paints the object. If isPainted()==false, we hide the oldLines
and no currentLines are drawn.
otherwise we hide the oldLines as well, but draw the currentLines
in the parent Grapics Context.
- Overrides:
- paint in class Component
toString
public String toString()
- Overrides:
- toString in class Component
All Packages Class Hierarchy This Package Previous Next Index