<html> <head> <title>User's Guide: Common Tasks</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="usersguide-9.html">Sketch's API </A></TD> <TD ALIGN="center"><A HREF="usersguide-5.html">User Scripting </A></TD> <TD ALIGN="right"></TD> </TR> </TABLE> <HR NOSHADE> <H2><FONT face="Helvetica,Arial"><A NAME="N1"></A>Common Tasks</font></H2> <P>Unless otherwise noted, all functions and classes mentioned here are directly accessible from the <CODE>Sketch</CODE> package. E.g. the <tt>CreateRGBColor</tt> function is accessible either with: <table width="100%" cellpadding="10"><tr><td bgcolor="#FFFFD0"> <PRE> import Sketch blue = Sketch.CreateRGBColor(0, 0, 1) </PRE> </td></tr></table> </P> <P>or</P> <P> <table width="100%" cellpadding="10"><tr><td bgcolor="#FFFFD0"> <PRE> from Sketch import CreateRGBColor blue = CreateRGBColor(0, 0, 1) </PRE> </td></tr></table> </P> <H3><FONT face="Helvetica,Arial"><A NAME="N2"></A>Creating Objects</font></H3> <P>Creating new objects for a drawing, usually takes three steps:</P> <P> <OL> <LI>Create the object. This is described in this section.</LI> <LI>Set graphics properties like fill color or line width. This is described <A HREF="#N19">below</A>.</LI> <LI>Insert the object into the document</LI> </OL> </P> <H4><FONT face="Helvetica,Arial"><A NAME="N3"></A>Primitives</font></H4> <H5><FONT face="Helvetica,Arial"><A NAME="N4"></A>Rectangles</font></H5> <P><A NAME="N5"></A><tt>Rectangle(<i>trafo</i>)</tt></P> <P>This function creates a rectangle object described by <i>trafo</i>. <i>trafo</i> is an affine transformation (represented by a <A HREF="devguide-7.html">a transformation object</A> that transforms the unit square into the desired rectangle.</P> <P>Transformation objects are created by the functions <A HREF="devguide-7.html#N3"><tt>Trafo</tt></A>, <A HREF="devguide-7.html#N4"><tt>Scale</tt></A>, <A HREF="devguide-7.html#N6"><tt>Rotation</tt></A> and <A HREF="devguide-7.html#N5"><tt>Translation</tt></A>. </P> <P>In the most common case where you want to create a rectangle with a specific width and height at a specific position (x, y) (the position of the lower left corner of the rectangle) and edges parallel to the edges of the page, you could create the rectangle like this:</P> <P> <table width="100%" cellpadding="10"><tr><td bgcolor="#FFFFD0"> <PRE> Rectangle(Trafo(width, 0, 0, height, x, y)) </PRE> </td></tr></table> </P> <P>or like this</P> <P> <table width="100%" cellpadding="10"><tr><td bgcolor="#FFFFD0"> <PRE> Rectangle(Translation(x, y)(Scale(width, height))) </PRE> </td></tr></table> </P> <H5><FONT face="Helvetica,Arial"><A NAME="N6"></A>Lines and Curves</font></H5> <P>All line and curve-objects in Sketch are instances of the <tt>PolyBezier</tt> class. Each <tt>PolyBezier</tt> object consists of one or more paths with each path consisting of one or more line or bézier segments.</P> <P>To create a <tt>PolyBezier</tt> object you have to first create the paths and then the <tt>PolyBezier</tt> instance. A path is created by starting with an empty path returned by the <A HREF="devguide-8.html#N3"><tt>CreatePath</tt></A> function and then appending line- and curve-segments to construct the path. How paths are constructed is covered in detail in the <A HREF="devguide-8.html">corresponding section in the developer's guide</A>.</P> <P>Once you have constructed your paths, you create the <tt>PolyBezier</tt> instance with:</P> <P><A NAME="N7"></A><tt>PolyBezier(<i>path_tuple</i>)</tt></P> <P>The argument <i>path_tuple</i> must be a tuple of paths. If you have just one path <CODE>path</CODE>, you can use the expression <CODE>(path,)</CODE>.</P> <P>For an example, see the sample script <tt>create_star.py</tt>.</P> <H5><FONT face="Helvetica,Arial"><A NAME="N8"></A>Text</font></H5> <P>Sketch's text capabilities are still very simple. A text object consists of just one line of text in one font and size, hence the class is called <tt>SimpleText</tt>:</P> <P><A NAME="N9"></A><tt>SimpleText(<i>trafo</i>, <i>text</i>)</tt></P> <P>Create a simple text object with the text string <i>text</i>. The position and orientation is given by <i>trafo</i>, a <A HREF="devguide-7.html">a transformation object</A>.</P> <P>For an example, see the sample scripts <tt>create_text.py</tt>.</P> <H4><FONT face="Helvetica,Arial"><A NAME="N10"></A>Compound Objects</font></H4> <H5><FONT face="Helvetica,Arial"><A NAME="N11"></A>Groups</font></H5> <P>Creating a normal group is very simple. First, you have to construct a list of the objects to be contained in the group. Then you just call the constructor:</P> <P><A NAME="N12"></A><tt>Group(<i>children</i>)</tt></P> <P>Create a group object with the objects in the list <i>children</i> as children. The children must not be contained in a document.</P> <P>If you want to create a group of objects that are already contained in the document, the easiest way is to make sure those objects are selected and then to call the document method <tt>GroupSelected</tt>. Like all document methods this method takes care of undo itself.</P> <H4><FONT face="Helvetica,Arial"><A NAME="N13"></A>Inserting the Object into the Document</font></H4> <P>You can insert an object into the document with this document method:</P> <P> <DL> <DT><B><A NAME="N14"></A><tt>Insert(<i>object</i>)</tt></B><DD> <P>Insert the object <i>object</i> into the document. The object becomes the topmost object in the current layer. The selection is set to just this object.</P> </DL> </P> <H3><FONT face="Helvetica,Arial"><A NAME="N15"></A>Manipulating Objects</font></H3> <P>Once you have created a graphics object or you have a reference to an object in the document, perhaps from the selection, you can manipulate them in various ways. All methods that modify an object in place return undo information which you have to pass to the document's <tt>AddUndo</tt> method if your script is an <A HREF="usersguide-6.html#N4">advanced script</A>.</P> <H4><FONT face="Helvetica,Arial"><A NAME="N16"></A>Transformations</font></H4> <P>Objects have two methods that allow you move and transform them.</P> <P><A NAME="N17"></A><tt>Translate(<i>offset</i>)</tt></P> <P>Move the object by <i>offset</i>. <i>offset</i> must be a <A HREF="devguide-5.html">point object</A>. For an example, see the sample scripts <tt>abut_horizontal.py</tt> and <tt>abut_vertical.py</tt>.</P> <P><A NAME="N18"></A><tt>Transform(<i>trafo</i>)</tt></P> <P>Apply the affine transformation <i>trafo</i> to the object.</P> <H4><FONT face="Helvetica,Arial"><A NAME="N19"></A>Changing Object Properties </font></H4> <P>Properties define how an object looks, i.e. they define the fill and line styles and fonts.</P> <P>The fill is defined by a pattern object. There are several kinds of pattern types:</P> <P> <DL> <DT><B><CODE>EmptyPattern</CODE></B><DD> <P>The <CODE>EmptyPattern</CODE> is a predefined object that means the object is not filled.</P> <DT><B><A NAME="N20"></A><tt>SolidPattern(<i>color</i>)</tt></B><DD> <P>Return a solid pattern object for color <i>color</i>. The solid pattern fills the object uniformly.</P> <P><i>color</i> has to be a color object which can be created with the following function:</P> <P><A NAME="N21"></A><tt>CreateRGBColor(<i>red</i>, <i>green</i>, <i>blue</i>)</tt></P> <P>which returns a color object for the color given by the RGB components <i>red</i>, <i>green</i>, <i>blue</i> which are floats in the range 0 - 1.</P> <P>There are also some predefined color objects for some standard colors. They are attributes of the <CODE>StandardColors</CODE> object, e.g. <CODE>StandardColors.blue</CODE> is blue.</P> </DL> </P> <P>There are more pattern like gradients which I haven't documented yet.</P> <P>To set the properties of an object, call this method</P> <P> <DL> <DT><B><A NAME="N22"></A><tt>SetProperties(<i>keyword_arguments</i>)</tt></B><DD> <P>Set the properties described by the keyword arguments and return undo information. The accepted keyword arguments are</P> <P> <DL> <DT><B>fill_pattern</B><DD> <P>The fill pattern. It can be of any pattern type.</P> <DT><B>fill_transform</B><DD> <P>A boolean (i.e. 0 or 1) that defines whether the pattern is transformed as well if the object is transformed.</P> <DT><B>line_pattern</B><DD> <P>The pattern for the outline. Must be either <CODE>EmptyPattern</CODE> or a <tt>SolidPattern</tt>. If it's <CODE>EmptyPattern</CODE>, no outline is drawn.</P> <DT><B>line_width</B><DD> <P>The line width as a float in pt.</P> <DT><B>line_cap</B><DD> <P>The cap style. One of <CODE>CapButt</CODE>, <CODE>CapRound</CODE> or <CODE>CapProjecting</CODE>. These constants are defined in <CODE>Sketch.const</CODE></P> <DT><B>line_join</B><DD> <P>The join style. One of <CODE>JoinMiter</CODE>, <CODE>JoinRound</CODE> or <CODE>JoinBevel</CODE>. These constants are defined in <CODE>Sketch.const</CODE></P> <DT><B>line_dashes</B><DD> <P>The dash-pattern as a tuple of floats. The items of the tuple define the dashes and gaps terms of the line-width. The number of items in the tuple should be even.</P> <DT><B>line_arrow1</B><DD> <DT><B>line_arrow2</B><DD> <P>The arrow heads. Arrow heads are objects you can create with the function <tt>Arrow</tt>.</P> <DT><B>font</B><DD> <P>The font for a text object. The value must be a font object which you can get with the function <A NAME="N23"></A><tt>GetFont(<i>name</i>)</tt> where <i>name</i> is the PostScript-name of the font.</P> <DT><B>font_size</B><DD> <P>The size of the font in pt.</P> </DL> </P> </DL> </P> <H3><FONT face="Helvetica,Arial"><A NAME="N24"></A>Managing the Selection</font></H3> <P>In Sketch 0.6.x, the selection is managed by the document object. You can use these document methods to query and change the selection:</P> <P> <DL> <DT><B><A NAME="N25"></A><tt>HasSelection()</tt></B><DD> <P>Return true if the selection is not empty.</P> <DT><B><A NAME="N26"></A><tt>CountSelected()</tt></B><DD> <P>Return the number of selected objects.</P> <DT><B><A NAME="N27"></A><tt>SelectedObjects()</tt></B><DD> <P>Return a list containing the currently selected objects.</P> <DT><B><A NAME="N28"></A><tt>CurrentObject()</tt></B><DD> <P>Return the currently selected object if exactly one object is selected, return None otherwise.</P> <DT><B><A NAME="N29"></A><tt>SelectNone()</tt></B><DD> <P>Make the selection empty.</P> <DT><B><A NAME="N30"></A><tt>SelectObject(<i>object</i>[, <i>mode</i>])</tt></B><DD> <P>If <i>mode</i> is <CODE>SelectSet</CODE>, make <i>object</i> the selected object, otherwise, if <i>mode</i> is <CODE>SelectAdd</CODE>, add <i>object</i> to the selection. <i>mode</i> defaults to <CODE>SelectSet</CODE>.</P> <P><i>object</i> may be a single object or a list of objects.</P> <DT><B><A NAME="N31"></A><tt>DeselectObject(<i>object</i>)</tt></B><DD> <P>Remove <i>object</i> from the selection.</P> </DL> </P> <HR NOSHADE> <TABLE WIDTH="100%"> <TR> <TD ALIGN="left"><A HREF="usersguide-9.html">Sketch's API </A></TD> <TD ALIGN="center"><A HREF="usersguide-5.html">User Scripting </A></TD> <TD ALIGN="right"></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>
