📄 137.html

📁 Tcl 语言的入门级图书
💻 HTML
字号:
<HTML><TITLE>Geometry Management: Placing Widgets more Carefully</TITLE><BODY BGCOLOR="#FFF0E0" VLINK="#0FBD0F" TEXT="#101000" LINK="#0F0FDD">
<A NAME="top"><H1>Placing Widgets more Carefully</H1></A>


<P>  For those cases in which a widget does not fill its associated slice,
the <TT>pack</TT> geometry manager has a way of positioning widgets within slices.
Similarly, the <TT>grid</TT> geometry manager has a way of positioning widgets within
cells.

<P>  Most of the time, the default positioning is just what you want.  With
this positioning the widget is placed in the center of the slice or cell.

<P>  When the default absolutely will not do, you use a technique that
depends on the geometry manager you are using.  

<A NAME="pstnngwdgtswthnslcs">
<H3>Positioning Widgets within Slices</H3></A>


<P>  The <TT>-fill</TT> option actually has four possible values: "none" (the
default), "both," "x," and "y."  The first two are discussed above in

<A HREF="13.3.html" tppabs="http://www.mapfree.com/sbf/tcl/book/select/Html/13.3.html">Slicing for Size Changes</A>.  The <TT>-fill x</TT> option causes the widget to fill its slice in
the horizontal directions but not in the vertical.  The <TT>-fill y</TT> option
causes the widget to fill its slice in the vertical directions but not in the
horizontal.

<P>  The <TT>pack</TT> command also accepts an <TT><NAME=#S13.7anchorpack>-anchor</A></TT> option that
can be used to pull the widget to one side or corner without making it bigger.
This option has nine possible values: "n," "e," "s," "w," "ne,"
"se," "sw," "nw," and "c."  Except for the last one, all these
values represent directions.  Think of a slice as a map.  The value of
<TT>-anchor</TT> will determine the direction in which you will find the widget
when the slice is larger than the widget.  The <TT>c</TT> option is the default
and it means the widget will be centered.

<P><CENTER><TABLE BORDER>
<CAPTION><ADDR>Figure 13.7a: Exercises 13.7a and 13.7b.</ADDR></CAPTION>
<TR ALIGN=center><TD><IMG SRC="F13x7a.JPG" tppabs="http://www.mapfree.com/sbf/tcl/book/select/Figs/F13x7a.JPG">
</TD></TR>
</TABLE></CENTER><P>

<P><A NAME="13.7a">
<STRONG>Exercise 13.7a</STRONG> </A><DL><DD>
  Reproduce Figure 13.7a with <TT>pack</TT> and by stretching
the window with your mouse.
<P> My solution uses five frames or boxes.
<P>
<A HREF="13.9.html#Sol13.7a" tppabs="http://www.mapfree.com/sbf/tcl/book/select/Html/13.9.html#Sol13.7a">Solution</A></DL>


<A NAME="pstnngwdgtswthnclls">
<H3>Positioning Widgets within Cells</H3></A>


<P>  Instead of the <TT>-fill</TT> and <TT>-anchor</TT> options, the <TT>grid</TT> geometry
manager has <TT><NAME=#S13.7stickygrid>-sticky</A></TT>.  The value of this option is a string
built up from four letters, "n," "e," "s," and "w," which again
represent directions.  A nonempty value of the <TT>-sticky</TT> option for a
widget will cause that widget to stick to each of the indicated sides.  If
there is just one letter, <CITE>L</CITE>, then the effect is like <TT>-anchor <CITE>L</CITE></TT>.
If there are multiple letters, the widget will touch every cell side in
every declared direction &#150; stretching as necessary to do so.  The value
"news," therefore, makes the widget fill the entire cell.

<P><A NAME="13.7b">
<STRONG>Exercise 13.7b</STRONG> </A><DL><DD>
  Reproduce Figure 13.7a with <TT>grid</TT> and by stretching
the window with your mouse. <P>
<A HREF="13.9.html#Sol13.7b" tppabs="http://www.mapfree.com/sbf/tcl/book/select/Html/13.9.html#Sol13.7b">Solution</A></DL>


<!-- Linkbar -->
<P><CENTER><FONT SIZE=2><NOBR>
<STRONG>From</STRONG>
<A HREF="javascript:if(confirm('http://www.mapfree.com/sbf/tcl/book/home.html  \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address.  \n\nDo you want to open it from the server?'))window.location='http://www.mapfree.com/sbf/tcl/book/home.html'" tppabs="http://www.mapfree.com/sbf/tcl/book/home.html">Tcl/Tk For Programmers</A><WBR>
<STRONG>Previous</STRONG>
<A HREF="13.6.html" tppabs="http://www.mapfree.com/sbf/tcl/book/select/Html/13.6.html">section</A><WBR>
<STRONG>Next</STRONG>
<A HREF="13.8.html" tppabs="http://www.mapfree.com/sbf/tcl/book/select/Html/13.8.html">section</A><WBR>
<STRONG>All</STRONG>
<A HREF="13.html" tppabs="http://www.mapfree.com/sbf/tcl/book/select/Html/13.html">sections</A><WBR>
<STRONG>Author</STRONG>
<A HREF="javascript:if(confirm('http://www.mapfree.com/mp/jaz/home.html  \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address.  \n\nDo you want to open it from the server?'))window.location='http://www.mapfree.com/mp/jaz/home.html'" tppabs="http://www.mapfree.com/mp/jaz/home.html">J. A. Zimmer</A><WBR>
<STRONG>Copyright</STRONG>
<A HREF="copyright.html" tppabs="http://www.mapfree.com/sbf/tcl/book/select/Html/copyright.html">Notice</A><WBR>
<P>
<I>Jun 17, 1998</I>
 </NOBR></FONT></CENTER></BODY></HTML>
⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -