referencedcanvas.html

Geotools是一个开源的Java GIS工具包,可利用它来开发符合标准的地理信息系统。Geotools提供了OGC(Open Geospatial Consortium)规范的一个实现来作为他们的

 could be the altitude at the event location. This value is typically to be appended
 to some other informations, like the event geographic coordinates.
 <p>
 This method queries registered <A HREF="../../../../org/geotools/display/canvas/ReferencedGraphic.html" title="class in org.geotools.display.canvas">graphics</A> in decreasing
 <A HREF="../../../../org/geotools/display/canvas/AbstractGraphic.html#getZOrderHint()">z-order</A> until one is found to formats a
 value.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>event</CODE> - The event.<DD><CODE>toAppendTo</CODE> - The destination buffer for formatting a value. The <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/StringBuffer.html" title="class or interface in java.lang"><CODE>StringBuffer</CODE></A>
         argument type allows efficient use of <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/text/Format.html" title="class or interface in java.text"><CODE>Format</CODE></A> for example.
<DT><B>Returns:</B><DD> if this method has formatted a value, or  otherwise.</DL>
</DD>
</DL>
<HR>

<A NAME="getToolTipText(org.geotools.display.event.ReferencedEvent)"><!-- --></A><H3>
getToolTipText</H3>
<PRE>
public <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A> <B>getToolTipText</B>(<A HREF="../../../../org/geotools/display/event/ReferencedEvent.html" title="interface in org.geotools.display.event">ReferencedEvent</A>&nbsp;event)</PRE>
<DL>
<DD>Returns the string to be used as the tooltip for a given event.
 This method queries registered <A HREF="../../../../org/geotools/display/canvas/ReferencedGraphic.html" title="class in org.geotools.display.canvas">graphics</A> in decreasing
 <A HREF="../../../../org/geotools/display/canvas/AbstractGraphic.html#getZOrderHint()">z-order</A> until one is found to returns a
 non-null string.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>event</CODE> - The event.
<DT><B>Returns:</B><DD>The tool tip text, or  if there is no tool tip for the given location.</DL>
</DD>
</DL>
<HR>

<A NAME="getAction(org.geotools.display.event.ReferencedEvent)"><!-- --></A><H3>
getAction</H3>
<PRE>
public <A HREF="http://java.sun.com/j2se/1.4/docs/api/javax/swing/Action.html" title="class or interface in javax.swing">Action</A> <B>getAction</B>(<A HREF="../../../../org/geotools/display/event/ReferencedEvent.html" title="interface in org.geotools.display.event">ReferencedEvent</A>&nbsp;event)</PRE>
<DL>
<DD>Returns the action to be used for a given event.
 This method queries registered <A HREF="../../../../org/geotools/display/canvas/ReferencedGraphic.html" title="class in org.geotools.display.canvas">graphics</A> in decreasing
 <A HREF="../../../../org/geotools/display/canvas/AbstractGraphic.html#getZOrderHint()">z-order</A> until one is found to returns a
 non-null action.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>event</CODE> - The event.
<DT><B>Returns:</B><DD>The action, or  if there is no action for the given location.</DL>
</DD>
</DL>
<HR>

<A NAME="getObjectiveCRS()"><!-- --></A><H3>
getObjectiveCRS</H3>
<PRE>
public final CoordinateReferenceSystem <B>getObjectiveCRS</B>()</PRE>
<DL>
<DD>Returns the objective Coordinate Reference System (the projection of a georeferenced CRS)
 for this . This is the "real world" CRS used for displaying all graphics.
 Note that underlying data in graphic primitives don't need to be in terms of this CRS.
 Transformations will be applied on the fly as needed at rendering time.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/display/canvas/AbstractCanvas.html#getObjectiveCRS()">getObjectiveCRS</A></CODE> in class <CODE><A HREF="../../../../org/geotools/display/canvas/AbstractCanvas.html" title="class in org.geotools.display.canvas">AbstractCanvas</A></CODE></DL>
</DD>
<DD><DL>
</DL>
</DD>
</DL>
<HR>

<A NAME="setObjectiveCRS(org.opengis.referencing.crs.CoordinateReferenceSystem)"><!-- --></A><H3>
setObjectiveCRS</H3>
<PRE>
public void <B>setObjectiveCRS</B>(CoordinateReferenceSystem&nbsp;crs)
                     throws TransformException</PRE>
<DL>
<DD>Sets the objective Coordinate Reference System for this .
 All graphic primitives are notified of the CRS change by a call to
 <code><A HREF="../../../../org/geotools/display/canvas/ReferencedGraphic.html#setObjectiveCRS(org.opengis.referencing.crs.CoordinateReferenceSystem)">setObjectiveCRS</A>(crs)</code>.
 <p>
 After the objective CRS change, this method invokes <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#setDisplayCRS(org.opengis.referencing.crs.DerivedCRS)"><CODE>setDisplayCRS</CODE></A>
 with a new, automatically computed, display CRS. The new display CRS try to preserve the
 same <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#getScale()">scale factor</A> than the previous one.
 <p>
 This method fires the following property change events in no particular order:
 {@value},
 {@value},
 {@value}.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/display/canvas/AbstractCanvas.html#setObjectiveCRS(org.opengis.referencing.crs.CoordinateReferenceSystem)">setObjectiveCRS</A></CODE> in class <CODE><A HREF="../../../../org/geotools/display/canvas/AbstractCanvas.html" title="class in org.geotools.display.canvas">AbstractCanvas</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>crs</CODE> - The objective coordinate reference system.
<DT><B>Throws:</B>
<DD><CODE>TransformException</CODE> - If the data can't be transformed.</DL>
</DD>
</DL>
<HR>

<A NAME="getDisplayCRS()"><!-- --></A><H3>
getDisplayCRS</H3>
<PRE>
public final DerivedCRS <B>getDisplayCRS</B>()</PRE>
<DL>
<DD>Returns the Coordinate Reference System associated with the display of this .
 Unless otherwise specified by a call to <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#setDisplayCRS(org.opengis.referencing.crs.DerivedCRS)"><CODE>setDisplayCRS</CODE></A>, the default
 display CRS assumes a rendering on a flat screen with axis oriented as in the
 <cite>Java2D</cite> default <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/awt/Graphics2D.html" title="class or interface in java.awt">user space</A>: Coordinates are
 in "dots" (about 1/72 of inch), <var>x</var> values increasing right and <var>y</var>
 values increasing <strong>down</strong>.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/display/canvas/AbstractCanvas.html#getDisplayCRS()">getDisplayCRS</A></CODE> in class <CODE><A HREF="../../../../org/geotools/display/canvas/AbstractCanvas.html" title="class in org.geotools.display.canvas">AbstractCanvas</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>See Also:</B><DD><A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#setDisplayCRS(org.opengis.referencing.crs.DerivedCRS)"><CODE>setDisplayCRS(org.opengis.referencing.crs.DerivedCRS)</CODE></A></DL>
</DD>
</DL>
<HR>

<A NAME="setDisplayCRS(org.opengis.referencing.crs.DerivedCRS)"><!-- --></A><H3>
setDisplayCRS</H3>
<PRE>
protected void <B>setDisplayCRS</B>(DerivedCRS&nbsp;crs)
                      throws TransformException</PRE>
<DL>
<DD>Sets the display Coordinate Reference System for this . The base CRS must be the <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#getObjectiveCRS()">objective CRS</A>,
 and the conversion from base is related to
 the map scale or zoom. This method is usually invoked by subclasses rather than users, as
 a consequence of zoom changes. For example this method may be invoked as a side-effect of
 the following methods:
 <p>
 <ul>
   <li><A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#setObjectiveCRS(org.opengis.referencing.crs.CoordinateReferenceSystem)"><CODE>setObjectiveCRS(org.opengis.referencing.crs.CoordinateReferenceSystem)</CODE></A></li>
   <li><A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#setObjectiveToDisplayTransform(org.opengis.referencing.operation.Matrix)"><CODE>setObjectiveToDisplayTransform(Matrix)</CODE></A></li>
 </ul>
 <p>
 This method fires a {@value}
 property change event.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>crs</CODE> - The display coordinate reference system.
<DT><B>Throws:</B>
<DD><CODE>TransformException</CODE> - If the data can't be transformed.</DL>
</DD>
</DL>
<HR>

<A NAME="getDeviceCRS()"><!-- --></A><H3>
getDeviceCRS</H3>
<PRE>
public final DerivedCRS <B>getDeviceCRS</B>()</PRE>
<DL>
<DD>Returns the Coordinate Reference System associated with the device of this .
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../org/geotools/display/canvas/AbstractCanvas.html#getDeviceCRS()">getDeviceCRS</A></CODE> in class <CODE><A HREF="../../../../org/geotools/display/canvas/AbstractCanvas.html" title="class in org.geotools.display.canvas">AbstractCanvas</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>See Also:</B><DD><A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#setDeviceCRS(org.opengis.referencing.crs.DerivedCRS)"><CODE>setDeviceCRS(org.opengis.referencing.crs.DerivedCRS)</CODE></A></DL>
</DD>
</DL>
<HR>

<A NAME="setDeviceCRS(org.opengis.referencing.crs.DerivedCRS)"><!-- --></A><H3>
setDeviceCRS</H3>
<PRE>
protected void <B>setDeviceCRS</B>(DerivedCRS&nbsp;crs)
                     throws TransformException</PRE>
<DL>
<DD>Sets the device Coordinate Reference System for this .
 This method is usually invoked by subclasses rather than users. At the difference of
 <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#setDisplayCRS(org.opengis.referencing.crs.DerivedCRS)"><CODE>setDisplayCRS(...)</CODE></A> (which is invoked everytime the zoom change),
 this method is usually invoked only once since the
 conversion from display CRS to derived CRS
 is usually constant.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>crs</CODE> - The device coordinate reference system.
<DT><B>Throws:</B>
<DD><CODE>TransformException</CODE> - If the data can't be transformed.</DL>
</DD>
</DL>
<HR>

<A NAME="setDisplayToDeviceTransform(org.opengis.referencing.operation.Matrix)"><!-- --></A><H3>
setDisplayToDeviceTransform</H3>
<PRE>
protected void <B>setDisplayToDeviceTransform</B>(Matrix&nbsp;transform)
                                    throws TransformException</PRE>
<DL>
<DD>Sets the <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#getDisplayCRS()">display</A> to <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#getDeviceCRS()">device</A> transform
 to the specified affine transform. This method creates a new device CRS and invokes
 <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#setDeviceCRS(org.opengis.referencing.crs.DerivedCRS)"><CODE>setDeviceCRS(org.opengis.referencing.crs.DerivedCRS)</CODE></A> with the result.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>transform</CODE> - The <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#getDisplayCRS()">display</A> to
         <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#getDeviceCRS()">device</A> affine transform as a matrix.
<DT><B>Throws:</B>
<DD><CODE>TransformException</CODE> - if the transform can not be set to the specified value.</DL>
</DD>
</DL>
<HR>

<A NAME="setObjectiveToDisplayTransform(org.opengis.referencing.operation.Matrix)"><!-- --></A><H3>
setObjectiveToDisplayTransform</H3>
<PRE>
public void <B>setObjectiveToDisplayTransform</B>(Matrix&nbsp;transform)
                                    throws TransformException</PRE>
<DL>
<DD>Sets the <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#getObjectiveCRS()">objective</A> to <A HREF="../../../../org/geotools/display/canvas/ReferencedCanvas.html#getDisplayCRS()">display</A>
 transform to the specified affine transform. This me