<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Using GTK+ on the X Window System: GTK+ 3 Reference Manual</title> <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot"> <link rel="home" href="index.html" title="GTK+ 3 Reference Manual"> <link rel="up" href="platform-support.html" title="Part VII. 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So you don't need to do anything special when compiling it, and everything should "just work." </p> <p> To mix low-level Xlib routines into a GTK program, see <GTKDOCLINK HREF="gdk-X-Window-System-Interaction">GDK X Window System interaction</GTKDOCLINK> in the GDK manual. </p> <p> GTK+ includes an cross-process embedding facility in the form of the #GtkSocket and #GtkPlug widgets. These are X11-specific, and you have to include the <code class="filename">gtk/gtkx.h</code> header to use them. </p> <div class="refsect2"> <a name="x11-cmdline"></a><h3>X11-specific commandline options</h3> <p> The X backend understands some additional command line arguments. </p> <p><b><code class="systemitem">--display <em class="replaceable"><code>display</code></em></code>. </b> The name of the X display to open instead of the one specified in the <code class="envar">DISPLAY</code> environment variable. </p> </div> <hr> <div class="refsect2"> <a name="x11-envar"></a><h3>X11-specific environment variables</h3> <p> The X11 GDK backend can be influenced with some additional environment variables. </p> <p><b><code class="envar">GDK_SYNCHRONIZE</code>. </b> If set, GDK makes all X requests synchronously. This is a useful option for debugging, but it will slow down the performance considerably. </p> <p><b><code class="envar">GDK_CORE_DEVICE_EVENTS</code>. </b> If set, GDK makes does not use the XInput extension, and only reacts to core X input events. </p> <p><b><code class="envar">GDK_SCALE</code>. </b> Must be set to an integer, typically 2. If set, GDK will scale all windows by the specified factor. Scaled output is meant to be used on high-dpi displays. Normally, GDK will pick up a suitable scale factor for each monitor from the display system. This environment variable allows to override that. </p> <p><b><code class="envar">GDK_DPI_SCALE</code>. </b> This can be useful when using scale-aware GTK+ applications together with scale-unaware applications on a high-dpi display. In that case, the font resolution can be doubled to make scale-unaware applications readable, and <code class="envar">GDK_DPI_SCALE=0.5</code> can be set to compensate for that in GTK+ applications which are already scaled by setting <code class="envar">GDK_SCALE=2</code>. </p> </div> </div> <div class="refsect1"> <a name="gtk-X11-arch"></a><h2>Understanding the X11 architecture</h2> <p> People coming from a Windows or MacOS background often find certain aspects of the X Window System surprising. This section introduces some basic X concepts at a high level. For more details, the book most people use is called the <em class="citetitle">Xlib Programming Manual</em> by Adrian Nye; this book is volume one in the O'Reilly X Window System series. </p> <p> Standards are another important resource if you're poking in low-level X11 details, in particular the ICCCM and the Extended Window Manager Hints specifications. <a class="ulink" href="http://www.freedesktop.org/standards/" target="_top">freedesktop.org</a> has links to many relevant specifications. </p> <p> The GDK manual covers <GTKDOCLINK HREF="gdk-X-Window-System-Interaction">using Xlib in a GTK program</GTKDOCLINK>. </p> <div class="refsect2"> <a name="id-1.8.5.4.5"></a><h3>Server, client, window manager</h3> <p> Other window systems typically put all their functionality in the application itself. With X, each application involves three different programs: the <em class="firstterm">X server</em>, the application (called a <em class="firstterm">client</em> because it's a client of the X server), and a special client called the <em class="firstterm">window manager</em>. </p> <p> The X server is in charge of managing resources, processing drawing requests, and dispatching events such as keyboard and mouse events to interested applications. So client applications can ask the X server to create a window, draw a circle, or move windows around. </p> <p> The window manager is in charge of rendering the frame or borders around windows; it also has final say on the size of each window, and window states such as minimized, maximized, and so forth. On Windows and MacOS the application handles most of this. On X11, if you wish to modify the window's state, or change its frame, you must ask the window manager to do so on your behalf, using an established <a class="ulink" href="http://www.freedesktop.org/standards/" target="_top">convention</a>. </p> <p> GTK+ has functions for asking the window manager to do various things; see for example <a class="link" href="GtkWindow.html#gtk-window-iconify" title="gtk_window_iconify ()">gtk_window_iconify()</a> or <a class="link" href="GtkWindow.html#gtk-window-maximize" title="gtk_window_maximize ()">gtk_window_maximize()</a> or <a class="link" href="GtkWindow.html#gtk-window-set-decorated" title="gtk_window_set_decorated ()">gtk_window_set_decorated()</a>. Keep in mind that <a class="link" href="GtkWindow.html#gtk-window-move" title="gtk_window_move ()">gtk_window_move()</a> and window sizing are ultimately controlled by the window manager as well and most window managers <span class="emphasis"><em>will</em></span> ignore certain requests from time to time, in the interests of good user interface. </p> </div> </div> </div> <div class="footer"> <hr>Generated by GTK-Doc V1.25.1</div> </body> </html>