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| <title>window(3) - Plan 9 from User Space</title> |
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| <tr><td width=20><td><b>WINDOW(3)</b><td align=right><b>WINDOW(3)</b> |
| <tr><td width=20><td colspan=2> |
| <br> |
| <p><font size=+1><b>NAME </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Screen, allocscreen, publicscreen, freescreen, allocwindow, bottomwindow, |
| bottomnwindows, topwindow, topnwindows, originwindow – window management<br> |
| |
| </table> |
| <p><font size=+1><b>SYNOPSIS </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>#include <u.h><br> |
| #include <libc.h><br> |
| #include <draw.h><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>typedef<br> |
| struct Screen<br> |
| {<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Display *display; /* display holding data */<br> |
| int id; /* id of system−held Screen */<br> |
| Image *image; /* unused; for reference only */<br> |
| Image *fill; /* color to paint behind windows */<br> |
| |
| </table> |
| } Screen;<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| Screen* allocscreen(Image *image, Image *fill, int public) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>Screen* publicscreen(Display *d, int id, ulong chan) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>int freescreen(Screen *s) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>Image* allocwindow(Screen *s, Rectangle r, int ref, int val) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>void bottomwindow(Image *w) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>void bottomnwindows(Image **wp, int nw) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>void topwindow(Image *w) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>void topnwindows(Image **wp, int nw) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>int originwindow(Image *w, Point log, Point scr) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>enum<br> |
| {<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| /* refresh methods */<br> |
| Refbackup= 0,<br> |
| Refnone= 1,<br> |
| Refmesg= 2<br> |
| |
| </table> |
| |
| </table> |
| };<br> |
| </font></tt> |
| </table> |
| <p><font size=+1><b>DESCRIPTION </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Windows are represented as <tt><font size=+1>Images</font></tt> and may be treated as regular |
| images for all drawing operations. The routines discussed here |
| permit the creation, deletion, and shuffling of windows, facilities |
| that do not apply to regular images. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| To create windows, it is first necessary to allocate a <tt><font size=+1>Screen</font></tt> |
| data structure to gather them together. A <tt><font size=+1>Screen</font></tt> turns an arbitrary |
| image into something that may have windows upon it. It is created |
| by <tt><font size=+1>allocscreen</font></tt>, which takes an <i>image</i> upon which to place the windows |
| (typically <tt><font size=+1>display−>image</font></tt>), a <i>fill</i> image |
| to paint the background behind all the windows on the image, and |
| a flag specifying whether the result should be publicly visible. |
| If it is public, an arbitrary other program connected to the same |
| display may acquire a pointer to the same screen by calling <tt><font size=+1>publicscreen</font></tt> |
| with the <tt><font size=+1>Display</font></tt> pointer and the <i>id</i> of the |
| published <tt><font size=+1>Screen</font></tt>, as well as the expected channel descriptor, |
| as a safety check. It will usually require some out-of-band coordination |
| for programs to share a screen profitably. <tt><font size=+1>Freescreen</font></tt> releases |
| a <tt><font size=+1>Screen</font></tt>, although it may not actually disappear from view until |
| all the windows upon it have also been |
| deallocated. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| Unlike <tt><font size=+1>allocwindow</font></tt>, <tt><font size=+1>allocscreen</font></tt> does <i>not</i> initialize the appearance |
| of the <tt><font size=+1>Screen</font></tt>. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| Windows are created by <tt><font size=+1>allocwindow</font></tt>, which takes a pointer to the |
| <tt><font size=+1>Screen</font></tt> upon which to create the window, a rectangle <i>r</i> defining |
| its geometry, an integer pixel value <i>val</i> to color the window initially, |
| and a refresh method <tt><font size=+1>ref</font></tt>. The refresh methods are <tt><font size=+1>Refbackup</font></tt>, which |
| provides backing store and is the |
| method used by <a href="../man1/rio.html"><i>rio</i>(1)</a> for its clients; <tt><font size=+1>Refnone</font></tt>, which provides |
| no refresh and is designed for temporary uses such as sweeping |
| a display rectangle, for windows that are completely covered by |
| other windows, and for windows that are already protected by backing |
| store; and <tt><font size=+1>Refmesg</font></tt>, which causes messages to be |
| delivered to the owner of the window when it needs to be repainted. |
| <tt><font size=+1>Refmesg</font></tt> is not fully implemented. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| The result of <tt><font size=+1>allocwindow</font></tt> is an <tt><font size=+1>Image</font></tt> pointer that may be treated |
| like any other image. In particular, it is freed by calling <tt><font size=+1>freeimage</font></tt> |
| (see <a href="../man3/allocimage.html"><i>allocimage</i>(3)</a>). The following functions, however, apply only |
| to windows, not regular images. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <tt><font size=+1>Bottomwindow</font></tt> pushes window <i>w</i> to the bottom of the stack of windows |
| on its <tt><font size=+1>Screen</font></tt>, perhaps obscuring it. <tt><font size=+1>Topwindow</font></tt> pulls window <i>w</i> |
| to the top, making it fully visible on its <tt><font size=+1>Screen</font></tt>. (This <tt><font size=+1>Screen</font></tt> |
| may itself be within a window that is not fully visible; <tt><font size=+1>topwindow</font></tt> |
| will not affect the stacking of this parent |
| window.) <tt><font size=+1>Bottomnwindows</font></tt> and <tt><font size=+1>Topnwindows</font></tt> are analogous, but push |
| or pull a group of <i>nw</i> windows listed in the array <i>wp</i>. The order |
| within <i>wp</i> is unaffected. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| Each window is created as an <tt><font size=+1>Image</font></tt> whose <tt><font size=+1>Rectangle r</font></tt> corresponds |
| to the rectangle given to <tt><font size=+1>allocwindow</font></tt> when it was created. Thus, |
| a newly created window <i>w</i> resides on its <tt><font size=+1>Screen−>image</font></tt> at <i>w</i><tt><font size=+1>−>r</font></tt> and |
| has internal coordinates <i>w</i><tt><font size=+1>−>r</font></tt><i>.</i> Both these may be changed by a call |
| to <tt><font size=+1>originwindow</font></tt>. The two |
| <tt><font size=+1>Point</font></tt> arguments to <tt><font size=+1>originwindow</font></tt> define the upper left corner of |
| the logical coordinate system (<i>log</i>) and screen position (<i>scr</i>). |
| Their usage is shown in the Examples section. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <a href="../man1/Rio.html"><i>Rio</i>(1)</a> creates its client windows with backing store, <tt><font size=+1>Refbackup</font></tt>. |
| The graphics initialization routine, <tt><font size=+1>initdraw</font></tt> (see <a href="../man3/graphics.html"><i>graphics</i>(3)</a>), |
| builds a <tt><font size=+1>Screen</font></tt> upon this, and then allocates upon that another |
| window indented to protect the border. That window is created |
| <tt><font size=+1>Refnone</font></tt>, since the backing store created by <tt><font size=+1>rio |
| </font></tt>protects its contents. That window is the one known in the library |
| by the global name <tt><font size=+1>screen</font></tt> (a historic but confusing choice).<br> |
| |
| </table> |
| <p><font size=+1><b>EXAMPLES </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| To move a window to the upper left corner of the display,<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>originwindow(w, w−>r.min, Pt(0, 0));<br> |
| </font></tt> |
| </table> |
| |
| </table> |
| To leave a window where it is on the screen but change its internal |
| coordinate system so (0, 0) is the upper left corner of the window,<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>originwindow(w, Pt(0, 0), w−>r.min);<br> |
| </font></tt> |
| </table> |
| |
| </table> |
| After this is done, <tt><font size=+1>w−>r</font></tt> is translated to the origin and there |
| will be no way to discover the actual screen position of the window |
| unless it is recorded separately.<br> |
| |
| </table> |
| <p><font size=+1><b>SOURCE </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>/usr/local/plan9/src/libdraw<br> |
| </font></tt> |
| </table> |
| <p><font size=+1><b>SEE ALSO </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <a href="../man3/graphics.html"><i>graphics</i>(3)</a>, <a href="../man3/draw.html"><i>draw</i>(3)</a>, <a href="../man3/cachechars.html"><i>cachechars</i>(3)</a>, <a href="../man3/draw.html"><i>draw</i>(3)</a><br> |
| |
| </table> |
| <p><font size=+1><b>BUGS </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| The refresh method <tt><font size=+1>Refmesg</font></tt> should be finished.<br> |
| |
| </table> |
| |
| <td width=20> |
| <tr height=20><td> |
| </table> |
| <!-- TRAILER --> |
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