Frequently Asked Questions (FAQ) about Dia

Contents

1. Metainformation

1.1. Who maintains this FAQ?

Steffen Macke < sdteffen@gmail.com >

1.2. Where can I find the newest version of this FAQ?

The newest version should always be available from dia-installer.de/doc/faq.html. Note that this is not the only version of a Dia FAQ. There's also one at wiki.gnome.org/Apps/Dia/Faq. This version is based on the Wiki version.

1.3. Who made this FAQ?

This FAQ was put together by Lars Clausen < lars@raeder.dk >. Most of the material came out of the Dia mailing list. The following people contributed more advice: Kerry < needles@industrialmusic.com >, James Henstridge < james@daa.com.au >, Simon Josefsson < simon@josefsson.org >, Jacek Pliszka < Jacek.Pliszka@fuw.edu.pl >, Steffen Macke, Robert Campbell < rob.campbell@visto.com >, Alan Horkan, and Hubert Figuiere < hfiguiere@teaser.fr >.

Wikification was done mainly by branko, Wolfgang Stoeggl, Steffen Macke and Lars Clausen. Further information on who has updated it since wikification can be found by clicking the Info link in the Page section of the wiki sidebar.

1.4. What's new in this version of the FAQ?

For change information, click the Info link in the Page section of the wiki sidebar or visit the internet archive.

1.5. How do you pronounce "Dia"?

The general consensus is to pronounce it "dee-a", not "die-a" (in IPA: ['diə]), following the pronunciation of the first part of the word "Diagram" in Swedish, the language of the original creator Alexander Larsson, and in the languages of most of the later maintainers. But if you pronounce it your way, we're not going to bring out the pitchforks and torches. We'll just be a little confused when we hear it.

2. General usage

2.1. How can I do anything but creating and moving objects?

You might ask this question if you don't have a menubar at the top of your diagram window. If you don't have such a menubar, please upgrade to the current version of Dia. Versions prior to 0.97 did not have a menubar at the top of the diagram window, but would show a menu if you clicked the right mouse button on the diagram.

2.2. I try to change diagram properties in the File > Preferences dialog, but nothing happens.

The preferences dialog only affects diagrams that are created thereafter. To change grid lines etc., go to the View menu and select settings there. The settings will be saved with the diagram.

2.3. I don't have a middle mouse button; what can I do?

Unix (XFree86): If EmulateThirdButton is enabled (which it should be if you have a two-button mouse), you can make a middle-button click by pressing both buttons simultaneously (an action also known as chording). Windows: If you don't have a middle mouse button, hold down the Ctrl key and use the right mouse button.

1.2.4. How can I set or change an accelerator key for a function in the menu?

This is possible since version 0.95; however, it may not be the most user-friendly way.

1. Find the file ".dia/menurc" in your home directory. That file would be:
   • C:\Documents and Settings\yourlogin\.dia\menurc on Windows prior to Vista, or
   • C:\Users\yourlogin\.dia\menurc on Windows Vista and newer, or
   • ~/.dia/menurc on *nix systems like Linux.
2. Make sure Dia is not running (shut it down if it is).
3. Open the file with a text editor (e.g. gedit in Linux, or in Windows by using Start->Run and typing notepad %USERPROFILE%\.dia\menurc ).
4. Find a line that contains the accelerator (shortcut) you wish to change. E.g., if you want to change the "Delete" key for Edit/Delete, this would be the line:
    ; (gtk_accel_path "<Actions>/display-actions/EditDelete" "Delete") 
   Let's say you want to change it to Control+Delete, so change the line to:
    (gtk_accel_path "<Actions>/display-actions/EditDelete" "<Control>Delete") 
   Notice that you have to remove the leading semicolon. The modifier keys (Ctrl, Alt, Shift) are written as <Control>, <Alt>, <Shift> and can be combined, e.g., "<Control><Shift>d" is a valid accelerator for Ctrl+Shift+d. Special keys such as Return, Insert, Delete are written as Return, Insert, Delete.
5. Save the file.
6. When you re-launch Dia, your new accelerator definitions should be in effect.

2.5. How can I set or change an accelerator key for one of the icons in the main window

These functions correspond to the items in the Tools menu. Set or change their accelerator keys there.

2.6. What are the five radio-buttons in the Select menu for?

They determine what happens when you drag-select objects. Normally (Replace), only the objects included in the drag area end up selected. By selecting other choices in the Select radio menu, you can change that behavior:

Union

Both the drag-selected objects and the previously selected objects end up selected.

Intersect

The only objects that end up selected are those that were already selected and were drag-selected.

Remove

Those previously selected objects that are in the drag area become unselected.

Invert

The objects in the drag area change selectedness: Unselected objects become selected, selected objects become unselected. The objects outside the drag area are not affected.

These operations correspond to set operations between the previously selected objects and the drag-selected objects.

2.7. How do I add bends to a zig-zag line

The right mouse button gives an object-specific menu. For zig-zag lines, polylines and Bézier lines, that menu allows you to add and remove bends (the menu options are called "Add segment" for zig-zag and Bézier lines and "Add Corner" for polylines). The following picture shows this:

For Bézier lines only, the same menu gives you a choice of how the control points (orange squares) can be moved around to produce different shapes of bend.

1. Symmetric control requires the 2 control points to be on a straight line with the node that's being edited on the Bézier line, and at equal distances from that node.
2. Smooth control requires the 2 control points to be on a straight line with the node, but they do not have to be equidistant from the node.
3. Cusp control lets you put the control points anywhere.

As you proceed down the above list, the curves that can be made with the Bézier line get progressively less smooth and more squiggly.

Following is an example. First, cusp control is selected from the menu:

Then, the Bézier line is made squigglier by putting both control points on the same side of the Bézier line:

2.8. How do I make a zig-zag line go horizontally

As of version 0.93, zig-zag lines (and objects derived from them, such as Dependency in UML) support a primitive form of autorouting that is intended to solve this problem and make it easier to make the diagrams look good. The autorouting algorithm does not attempt to avoid objects, but should at least make the lines go the right direction out from connection points. If it doesn't appear to work, double-click the zig-zag line and check that autorouting is on for it. This setting can also be accessed from the object menu (first make sure the object is selected; if it is not selected, click the left mouse button on the object to select it; then click the right mouse button to bring up the object menu).

For previous versions, here is a workaround for how to make zigzags change direction:

Using the object-specific menu, create an extra segment at each end of the line, then delete the middle segment:

1. 
2. 
3. 
4. 
5. 

2.9. How do I change the properties of several objects at a time?

This is supported starting with version 0.97. If you have a prior version of Dia, please upgrade.

2.10. Why can't I resize classes etc.

The size of classes is decided by their contents, especially the text. You can scale the entire diagram when you print; see the question about page fitting.

2.11. Why do elements have a fixed number of connection points

We've been thinking about how to allow more connection points. Point is, there are several different ways it could be done that all make sense, and we'd like to get the most usable of them, while maintaining backwards compatibility. Adding connection points in general is a tricky problem, as it is difficult to make sure that the points keep their placement after a reload. The standard Line object allows you to add more connection points to it by the right-mouse-button menu (first use the left mouse button to select the line so that the right-mouse-button menu will operate on that Line object). You can, in a pinch, place a line along the edge of an object and use the line's connection points.

2.12. Why can't Dia rotate arbitrarily?

While the GDK rendering engine provides support for rotated text, having rotated text is only part of the problem. We also need infrastructure so that handles, connection points, bounding boxes etc. are rotated along with the object. Help on this would be appreciated. If you are a software developer, please make sure to check the git master version to see the latest information about rotation support in Dia.

2.13. Why can't I add more connection points to objects?

See above.

2.14. Why don't the fonts work right?

Font support is not very standard in X, especially when you want to make images, print, and send the files to other people.

In Dia version 0.90 and earlier, you can improve things by installing the urw-aliases package (or the GhostScript fonts).  After installing the package, you will need to do a simple edit of a config file.  Edit /etc/X11/fs/config and move the line /usr/share/fonts/default/urw-aliases to just below the ...:unscaled lines (make sure the commas are in the correct places after making the change).  Then run killall -USR1 xfs to get the font server to reread its config file.  The URW fonts should be used in place of the adobe ones they are clones of when an unscaled bitmap version can't be found.

As of 0.91, Dia on Unix uses the FreeType library to provide better font support.  The fonts for this are, in turn, controlled by font-config.  Note that this means that remote fonts servers cannot be used.

As of 0.96, fonts should keep their width correctly when zoomed in and out.  However, due to differences in font rendering engines and in fonts available, the width may not be the same when moving files between computers, and particularly when moving between Windows and Unix.

A detailed history of font handling in Dia is available on the Apps/Dia/Fonts page.

2.15. The fonts are unreadably tiny, either on screen or when writing PNG.

This should only be an issue for versions 0.92 to 0.94. If you are using any of these versions, you should upgrade.

Dia 0.91 assumed things about Pango that weren't guaranteed, but didn't make a difference at the time. However, Pango 1.2.4 and up changed so that Dia's wrong assumptions now cause problems. This is fixed in Dia 0.92.1. Alternatively, if you can't install 0.92.1, you can downgrade your Pango to below 1.2.4. We highly recommend using the newest version of Dia, though.

In Dia 0.92-0.94, we used a reworked cache which still didn't quite keep different sizes of the same text apart, so text would change size between huge, tiny and normal. In 0.95, the cache is disabled.

2.16. How do I use Dia in English (or other language) when my Operating System is set to a different language

The recommended way to change the language in Dia is to change the Operating System language and Dia will follow the default.

However, many people have asked if they can use Dia in a language other than the current set default language. If the language you want is English, the easiest approach is to move or remove the language files (.mo) and allow the default English to show through instead.

There is also a slightly more complicated approach whereby you set the locale variable on the command line.

You may also want to see "How can I use Dia in German on Windows?".

2.17. Why can't I select anything after loading a diagram?

Check the layers dialog. The active layer didn't get saved with the file. None of the objects you are trying to select are on the default layer.

2.18. How can I define a standard font size for an object?

Double-click on the object in the toolbox to open a dialog that allows you to specify a default font size for the object.

2.19 How can I use Dia in German on Windows

Of course, this question also applies to other languages. There is a number of things to check/know:

• Make sure that Windows uses German translations.
• Selecting "German" during the Windows installation process of Dia will not cause Dia to use German translations.
• It is important that you select the "Translations" component during the installation process. If the translations are not installed, Dia will operate in English exclusively. If you're not sure if you have installed the translations, simply repeat the installation and install the translations.
• There are some rare cases where Dia's language detection fails. In these cases a simple batch file can be used to start Dia in the correct language. For German, dia_de.bat can be used. The file has to be copied to C:\Program Files (x86)\Dia\bin on 64-bit versions of Windows or C:\Program Files\Dia\bin on 32-bit versions - assuming that the default installation path was not changed. In case these folders do not exist on your system, please locate the bin folder of your Dia installation.

You may also want to see "How do I use Dia in English (or other language) when my Operating System is set to a different language?".

2.20 How can I use rulers with inches?

Unfortunately, this is currently impossible. See bug #133644 for the details.

3. Saving and Printing

3.1. What format is the .dia file

The native Dia file format (extension .dia) is XML compressed with GZip. You can select not to compress the files in File > Preferences > Diagram Defaults ("Compress saved files" option) or in the save dialog.

3.2. How can I scale the diagram to fit a page

In the Page Setup dialog (selected from File/Page Setup), select Fit to:, and the blue lines will continuously self-adjust to fit to a page (or several pages).

3.3. How do I use an exported TeX/PSTricks file in my TeX document

First add \usepackage{pstricks} to the preamble of your TeX document. Then include your image as

 \begin{figure
 \centering
 \input{filename.tex}
 \caption{A caption
 \labelfigure:alabel
 \endfigure

in your document.

Note: PSTricks in the tetex-1.0.6-11 RPM (used in Red Hat Linux 6.2) is buggy. Easiest fix is to get pstricks.tex from CTAN and put it in /usr/share/texmf/tex/generic/pstricks/.

3.4. I wish I had nice zigzags and coils as in PSTricks. How could I get them

Draw them as standard lines in dia. Then in the .tex file replace \psline with \pccoil or \pczigzag. For more information on their arguments, look into your PSTricks documentation included in your PSTricks package or at PSTricks home page. Careful! Lines with more than one segment have to be split into separate segments when pccoil and pczigzag are used.

3.5. How do I put (La)TeX formulas on my diagram

Put them as you would put them in TeX, e.g.: $\delta^\dagger_2$. At the moment of writing this FAQ it is not yet displayed correctly in Dia, but the TeX code produced should be fine. The bounding-box of the formula will not be calculated correctly. We're hoping for some kind, LaTeX-loving soul to implement the interface to TeX that will allow us to get a bitmap rendering of the TeXified output. It probably would require some way to set TeX invocation string, preamble and postamble.

3.6. Why is printing broken

Dia has several ways to print: Dia print, Gnome print and Export as PostScript. A given compilation of Dia uses either Dia print or Gnome print. Dia's support for Gnome print is currently buggy and disabled by default, but some distributions (Red Hat for one) compile it in anyway. If you have such a version of Dia installed, you can Export as PostScript instead of printing, and then print the resulting file.

3.7. How can I use Dia to convert files without running X

Version 0.94 of Dia should be able to convert files without running X. However, a working installation of GTK is required to link the program, and Pango must be available for text conversion.

Earlier versions of Dia depend on X for various things, but it is planned to allow conversions without running X. In the meanwhile, you can use Xvbf to simulate an X server with the command:

startx "/usr/bin/env DISPLAY=:1 /usr/bin/dia -e $HOME/tmp/foo.png $HOME/tmp/foo.dia" -- /usr/!X11R6/bin/Xvfb :1 -once -nolisten tcp

Thanks to Basile Starynkevitch for this hint.

3.8. How do I make Dia use PostScript fonts instead of Pango rendering

The current PostScript output on systems with font-config involves rendering the fonts as Bézier curves. This gives an (almost) perfect output, but doesn't allow PostScript tools to operate on the fonts. If you want to get output using PostScript fonts, use the EPS export filter marked as "using PostScript Latin-1 fonts". To use this from the command line for conversions, add --export-to-format=eps-builtin to the command line.

Note that this export doesn't support other encodings than Latin-1 and is limited to the "standard 13" set of fonts. Please don't ask us to add other encodings to this. We will not do it. It's an interim solution while we try to get embedded fonts out of Pango (maybe using PangoPDF) or find a proper way to include partial fonts.

3.9. When printing I get many pages of text starting with: %!PS-Adobe-2.0. What to do

Buy a PostScript printer or implement GDI printing ... The other option is to install Ghostscript along with its print redirector so you can have a Windows printer that filters things through gs.

4. Compiling Dia

4.1. Why can't I compile Dia

In most cases, it is because you have an old version of a support library. The libraries needed to compile Dia version 0.91+ are:

• pkg-config version 0.14.0 or higher.
• GTK version 2.0.0+
• and related libraries (glib, atk, pkg-config, pango). Pango version 1.1.5 or higher. Must be compiled with the PangoFT2 module. Pango 1.1.5 and higher depend on GLib version 2.1.3 or higher. PangoFT2 depends on font-config version 1.0.1 or higher.
• libxml version 2.3.9 or higher
• intltool version 0.21 or higher.
• freetype version 2.0.9 or higher on Unix.

Optional libraries that add extra features (for 0.91+):

• libpng (for png export support)
• gnome-libs (for Gnome support)
• libart version 2.1.0 or higher, for antialiasing and PNG export support.
• libxslt for the XSLT plug-in.
• Python and PyGtk2 for Python support

The libraries needed to compile Dia as of version 0.90 are:

• Glib version 1.2.0+ (required by GTK)
• GTK version 1.2.0+
• Gdk-Pixbuf version 0.7.0+ (can be replaced with Imlib version 1.8.0+)
• libxml version 1.8.5+
• intltool version 0.12 or higher.
• libunicode
  • version 0.4 (not the version 0.7 available at SourceForge). Optional libraries that add extra features (for 0.90):
• libpng (for png export support)
• gnome-libs (for Gnome support)
• bonobo (for document embedding support, requires Gnome)
• freetype version 2.0.9 or higher, for better font support.
• libart version 2.1.0 or higher, for antialiasing and PNG export support.

If you use a package system (dpkg or RPM), you will need to download the development packages (-dev or -devel).

Some systems, notably Red Hat and derivatives, don't have /usr/local/lib in /etc/ld.so.conf. GNU applications by default install into /usr/local when compiled. To make Dia work there, either add /usr/local/lib to /etc/ld.so.conf and run ldconfig as root, or configure with --prefix=/usr to put everything in /usr.

Note that Dia is included in many Linux distributions. You can start building from these packages.

If you're trying to compile on Windows or OS X, please have a look at How to compile Dia.

4.2. How can I convert the tar file to an rpm

As of version 0.95, Dia does not attempt to update its own .spec file, simply because there are too many differences between distributions. Please check your favorite RPM-based Linux distribution for the SPEC files they're using to build the Dia RPMs.

4.3. Can Dia compile on Mac OS X

Yes. This webpage mentions how.

4.4. Why does my copy of Dia for Windows die when I try to load it

Because the HOME environment variable is not set. Add a line like this to your autoexec.bat file:

•  set HOME=c:\home 

then restart your computer and make sure c:\home exists. The path should not contain any spaces and is case-sensitive (c:\Home is not the same as c:\home).

As of Dia 0.88.1, this problem should be fixed.

5. Extending Dia

5.1. How do I make patches for Dia so that they are integrated with minimum delay

Please see the Apps/Dia/HowToSubmitPatches page.

5.2. After compiling, when I run Dia it fails with the following error:

"Couldn't find standard objects when looking for object-libs, exiting..."

You're trying to run the Dia executable directly from the source directories. Either do make install, or run with the wrapper script app/run_dia.sh. That way, Dia will know where to find its objects.

5.3. How do I add new shapes/sheets?

Have a look at How to add a new shape to Dia.

An explanation on how the shape format works is given in doc/custom-shapes in the source distribution.

Sam Liddicott has provided a combination of an XSLT and a shell script that will make a shape from an ordinary SVG file, including connection points. With this, it should be easy to create shapes with, say, Inkscape.

However, Dia now also has the capability of exporting a diagram as a shape. Each collection of shapes (called a sheet) should be kept together in a subdirectory of ~/.dia/shapes, e.g, ~/.dia/shapes/Engines. To make a shape, first design it in Dia. Then export it into your subdirectory. Two files will be generated, a .shape file and a .png file (the icon).

From version 0.90 and up, Dia features a Sheets and Objects editor (accessible as File > Sheets and Objects...) which will allow you to load the shape into a sheet. It will also update Dia's loaded objects on the fly.

If you still want to do things by hand, update the corresponding sheet file in ~/.dia/sheets, in this case called Engines.sheet. Example contents of a sheet file:

 <?xml version="1.0" encoding="iso-8859-1"?> <!-- -*- xml -*- -->
 <sheet xmlns="http://www.lysator.liu.se/~alla/dia/dia-sheet-ns">
   <name>Engines</name>
   <description>Mechanical Engines</description>
   <contents>
     <object name="Engines - Gas">
       <description>A gas engine</description>
     </object>
   </contents>
 </sheet>

Each new object should be added to the sheet by adding an object section. Next time you restart Dia, the new objects should show up in the list of sheets.

If you want your sheets and shapes included in Dia, please create a .sheet.in file where the name and description tags are replaced by _name and _description, respectively. This allows us to have an external translation of the sheets. The sed script below outputs a .sheet.in file from a .sheet file:

 sed 's!<name>!<_name>!;s!</name>!</_name>!;s!<description>!<_description>!;s!</description>!</_description>!;'

5.4. Can Dia open Visio .vsd files?

No, it can't. Visio file format is a completely proprietary and undocumented file format. So it is really difficult to write code to read it. The now-defunct Software Bazaar offered a bounty of several thousand dollars for reverse-engineering the Visio format. We really would like to be able to do so.

With Visio 2002, it has become possible to export Visio diagrams as XML (.vdx). Microsoft, in their infinite generosity, has even published the Schema. Ian Redfern has made use of this, and a VDX importer/exporter is part of Dia as of version 0.96.

With the availability of libvisio, it would be possible to write a VSD file importer for Dia. While this has not been done yet, you can use tools like vsd2svg to convert your VSD files into SVG, which can in turn be imported or embedded in Dia.

An alternative would be to make a Visio plug-in that will allow conversion. Other programs have already done this for their proprietary formats. If somebody were to make such a script, we could set up a public server to do conversions.

6. Licensing

6.1. Under what license is Dia released?

Dia is released under the GPL, version 2. The full text and more information about the GPL can be found here.

6.2. Under what license are any diagrams I create in Dia held?

As explained on the GPL website, the developers of Dia have no claim to any diagrams you create using Dia. Therefore, you are free to license any diagrams you create with Dia however you wish.

If you are looking for an open license with which to license your diagrams, you might want to consider the Creative Commons.