<html> <head> <title>Developer's Guide: The class GraphicsObject</title> </head> <body bgcolor=white text=black link=blue vlink=navy alink=red> <TABLE WIDTH="100%"> <TR> <TH ALIGN="left" WIDTH="33%"><img SRC="Images/arrow-left.png" WIDTH="16" HEIGHT="16" ALIGN="top" ALT="Prev"></TH> <TH ALIGN="center" WIDTH="33%"><img SRC="Images/arrow-up.png" WIDTH="16" HEIGHT="16" ALIGN="top" ALT="Up"></TH> <TH ALIGN="right" WIDTH="33%"><img SRC="Images/arrow-right.png" WIDTH="16" HEIGHT="16" ALIGN="top" ALT="Next"></TH> </TR> <TR> <TD ALIGN="left"><A HREF="devguide-10.html">Class Hierarchy </A></TD> <TD ALIGN="center"><A HREF="devguide-9.html">The Document and Graphics Classes</A></TD> <TD ALIGN="right"><A HREF="devguide-12.html">The class Bounded </A></TD> </TR> </TABLE> <HR NOSHADE> <H2><FONT face="Helvetica,Arial"><A NAME="N1"></A>The class <A NAME="N2"></A><tt>GraphicsObject</tt></font></H2> <P>Base Classes: <A HREF="devguide-12.html#N2"><tt>Bounded</tt></A>, <A HREF="devguide-13.html#N2"><tt>HierarchyNode</tt></A>, <A HREF="devguide-15.html#N2"><tt>Selectable</tt></A> and <A HREF="devguide-14.html#N2"><tt>Protocols</tt></A>.</P> <P>The class <tt>GraphicsObject</tt> defines the interface common to all graphics objects.</P> <P>For convenience of implementation, and because their interfaces are needed elsewhere in the class hierarchy as well, some parts of this interface are defined by the base classes:</P> <P> <DL> <DT><B><A HREF="devguide-12.html#N2"><tt>Bounded</tt></A></B><DD> <P>provides instance variables for the vertical and horizontal dimensions of a graphics object and some related methods.</P> <DT><B><A HREF="devguide-13.html#N2"><tt>HierarchyNode</tt></A></B><DD> <P>provides the default behavior for all methods related to the management of the object hierarchy in the document.</P> <DT><B><A HREF="devguide-15.html#N2"><tt>Selectable</tt></A></B><DD> <P>defines the generic interface and default behavior for selection.</P> <DT><B><A HREF="devguide-14.html#N2"><tt>Protocols</tt></A></B><DD> <P>has some variables that describe the object's capabilities.</P> </DL> </P> <H3><FONT face="Helvetica,Arial"><A NAME="N3"></A>Instance Variables</font></H3> <P><tt>GraphicsObject</tt> maintains no instance variables of its own, but uses those managed by its base classes.</P> <H3><FONT face="Helvetica,Arial"><A NAME="N4"></A>Methods</font></H3> <P>Methods defined in <tt>GraphicsObject</tt>:</P> <P> <DL> <DT><B><A NAME="N5"></A><tt>Blend(<i>other</i>, <i>frac1</i>, <i>frac2</i>)</tt></B><DD> <P>Return the weighted average of <i>self</i> and <i>other</i>. <i>frac1</i> and <i>frac2</i> are the weights (if <i>self</i> and <i>other</i> were numbers this should be <i>frac1</i> * <i>self</i> + <i>frac2</i> * <i>other</i>).</P> <P>This method is used by the function <tt>Blend</tt> in <tt>blend.py</tt>. If <i>self</i> and <i>other</i> can't be blended, raise the <CODE>blend.Mismatch</CODE> exception. This is the default behavior.</P> <DT><B><A NAME="N6"></A><tt>AsBezier()</tt></B><DD> <P>Return self as a <tt>PolyBezier</tt> object if possible. If this is not possible, return <CODE>None</CODE>.</P> </DL> </P> <P>The following methods are not implemented in <tt>GraphicsObject</tt> directly, but must be defined for every graphics object. The derived classes <A HREF="devguide-16.html#N2"><tt>Primitive</tt></A> and <A HREF="devguide-17.html#N2"><tt>Compound</tt></A> provide a default implementation for most objects.</P> <P> <DL> <DT><B><A NAME="N7"></A><tt>Transform(<i>trafo</i>)</tt></B><DD> <P>Apply the <A HREF="devguide-7.html">transformation object</A> <i>trafo</i> to self. Return undo info.</P> <DT><B><A NAME="N8"></A><tt>Translate(<i>offset</i>)</tt></B><DD> <P>Translate (move) self by <i>offset</i>. <i>offset</i> is a <A HREF="devguide-5.html">point object</A>. Return undo info.</P> <DT><B><A NAME="N9"></A><tt>DrawShape(<i>device</i> [, <i>clip</i>])</tt></B><DD> <P>Draw self on <i>device</i>. <i>device</i> is a graphics device .</P> <P>The optional parameter <i>clip</i> is only provided if the object is used as a clip mask. If it is provided its value is 1. Objects that can be used as clip masks (their <CODE>is_clip</CODE> flag is true) request appropriate clipping from the graphics device. Objects that cannot be used as clip masks don't need to accept it.</P> <P>(Note: The clipping interface for the high level drawing operations of the graphics devices is somewhat experimental)</P> <DT><B><A NAME="N10"></A><tt>SaveToFile(<i>file</i>)</tt></B><DD> <P>Save self to file. The argument <i>file</i> is currently an instance of the class <tt>SKSaver</tt> which provides special methods for the object types currently implemented in Sketch.</P> </DL> </P> <HR NOSHADE> <TABLE WIDTH="100%"> <TR> <TD ALIGN="left"><A HREF="devguide-10.html">Class Hierarchy </A></TD> <TD ALIGN="center"><A HREF="devguide-9.html">The Document and Graphics Classes</A></TD> <TD ALIGN="right"><A HREF="devguide-12.html">The class Bounded </A></TD> </TR> <TR> <TH ALIGN="left" WIDTH="33%"><img SRC="Images/arrow-left.png" WIDTH="16" HEIGHT="16" ALIGN="top" ALT="Prev"></TH> <TH ALIGN="center" WIDTH="33%"><img SRC="Images/arrow-up.png" WIDTH="16" HEIGHT="16" ALIGN="top" ALT="Up"></TH> <TH ALIGN="right" WIDTH="33%"><img SRC="Images/arrow-right.png" WIDTH="16" HEIGHT="16" ALIGN="top" ALT="Next"></TH> </TR> </TABLE> </body> </html>
