This chapter describes the Interchange window in detail.

The Interchange window has three parts.

On the left side, you choose the files to convert. The left side contains the familiar Windows elements found in any file dialog, such as the name of the current directory, a list box containing directory names, a combo box containing disk drives, a filename that accepts wildcards, and a list box of files in that directory.

In the center part, there is a list box containing the filenames that will be translated when Convert is pressed. On the right side, you choose the directory where converted files will be stored. Like the left side, the right side contains acts like any file dialog.

As you choose each file to convert, it moves to the center Selected Files list box.

The right side shows the files that will be translated, where the resulting converted files will be stored, and to which format they will be converted.

Source Directory
This shows the path of the current directory. You can enter a new path here to select another directory.

Source Drives
This combo box contains a list of all the disk drives on your system. It selects the drive of the current directory for choosing files to convert.

Source File Name
This edit control shows the wildcard used to filter the list of files in the current directory. By default, the wildcard is set to "*.*", so all files are shown.

When you choose a new import type in Import Format combo box, a new wildcard is set. The list of files is updated to show only those filenames that match the wildcard.

The wildcard can be composed of several wildcard specifications, separated by a semi-colon. For example, a wildcard of "*.3DS;*.PRJ" shows all files that end in ".3DS" and ".PRJ".

You can use this edit control to quickly change drive and directory. For example, you can quickly change to the D: drive and the SAMPLES directory by entering "D:\samples" and pressing Enter.
You can also enter a filename here. If the file exists, then it is immediately added to the Selected files list box.

Source Files list box
The Source Files list box is unlabeled, but resides directly below the Source File Name string. This list box shows the files in the current directory, as filtered by the wildcard in the Source File Name edit control.

To select a file for conversion, click it with the mouse. A single click highlights the filename. A double-click copies the filename to the Selected files list box.

You can highlight a range of filenames in one operation. Click on the first file in the range of filenames. Then hold down the shift key and click on the last filename in the range of files to select.

You can modify the selection by holding down the Ctrl key and clicking on filenames.

To add all highlighted files to the Selected Files list box, click Add. To add all highlighted and non-highlighted filenames in the list box to the Selected Files box, click Add All.

Add
To choose files for conversion, highlight them in the Source Files list box, then click "Add."

Add All
To add all files in the Source Files list box to the Selected Files list box, click "Add all".

Import Format
This combo box shows all of the file formats that Interchange can import and convert to other formats. Choosing a new format in this drop-down list replaces the wildcard used to filter the list of files in the current directory. Each Converter's entry includes a typical wildcard used by files of this type. For example, AutoCAD DXF files typically have the extension ".DXF".

The wildcard "*.DXF" is copied to the Source File Name. If there are any files that end in ".DXF" in the current Source File directory, then they appear in the Source Files list box. If no ".DXF" files are in the current directory, then the list box will be empty.

Note that some formats do not have a typical extension, so the wildcard "*.*" is shown instead, which shows all available files and does not filter the list of files in any way.

Options
Many Interchange Converters have a dialog for setting options that control the way that particular data will be imported or exported.

Clicking the Options button next to the Import Format combo box brings up the dialog for the currently selected Converter. These options are persistent. The next time you run Interchange, they will be the same. Note that some Converters do not have any options. These have an Options dialog with only an "OK" button.

Help and About
Every Converter's Option dialog has a Help button that invokes your system's Web browser with documentation for that Converter. These documents are stored in your Interchange installation directory. Each Converter has an About button that shows the Converter's version number, name of the DLL, and the exact file size and creation date.

Convert button
Clicking the Convert button begins a batch conversion of all Selected Files. You must have at least one file in the Selected Files list box to convert.

After selecting files for conversion and choosing an Output Format, begin the conversion by single-clicking the Convert button.

During the conversion process, a status dialog appears. The title describes whether an import or an export is happening, as well as the file format and filename.

Up to three lines of rapidly changing status information appear in the dialog, too. Conversion of small objects may take place so rapidly that you may not have time to read these messages.
The Stop button on the status dialog will halt a conversion at any time. Stopping a conversion is regarded as an error. The import or export operation may take several moments to clean up. "Freeing" status messages appear during this time.

Finally, an error dialog appears:

Selected Files
This list box holds the full filename paths of all files that will be converted when the Convert button is clicked.

Remove
This button operates on any highlighted filenames in the Selected Files list box. Clicking Remove will clear the filenames from the list box.

Remove All
Clicking on this button clears all filenames from the Selected Files list box.

Destination Directory
This shows the path of the destination directory. Any files you convert will be stored here. You can easily change this path and select another directory.

Destination Drives
This combo box contains a list of all the disk drives on your system. It selects the drive of the directory that will hold the converted files.

Destination Directory Name
Entering a filename here has no effect, but you can change the wildcard to filter which files are shown. You cannot directly control the filename of a converted file. Interchange automatically creates a destination filename from the base filename of the original file plus the proper extension for the destination file format.

Export Format
This combo box shows the formats that Interchange can export. This contains a slightly different list of file types than those in the Import Format combo box. Some Converters only import a certain format, others can only export a particular format.

Options
This is similar to the other Options button next to the Import Format combo box. Clicking this button opens the options dialog box for the Converter for the currently selected Export Format.

For more information about Options dialogs, see the above description of the other Options button.

Conversions / Options menu item
The leftmost menu on the Interchange window is Conversions. The Options menu item invokes the Interchange Options dialog:

Options / Filenames
This group of options controls the appearance of filenames in the list boxes. On MS-DOS drives, filenames are all upper-case. On Windows NT and Windows 95 drives using NTFS partitions, filenames can be both upper- and lower-case.

When Keep mixed case is checked, Windows NT filenames on NTFS drives will preserve the mixed-case filenames. MS-DOS filenames appear in upper-case.

When Lower case for DOS is checked, Windows NT filenames will continue to be shown in mixed case, while DOS filenames will be forced to lower case.

Checking All lowercase forces all filenames to lower-case.

Options / File recognition
These options control Interchange's automatic recognition of files. To recognize the format of any file, Interchange asks each available Converter if it can recognize the file. In an ideal situation, only one Converter will recognize the file. Unfortunately, some file formats are so free-form that they are difficult for computer programs to recognize. A single file might be recognized by two different Converters.

When querying Converters, Interchange first believes the extension of the file. For example, if the filename's extension is ".3DS", then Interchange first queries the 3D Studio Converter.

When Believe first recognized format is set, Interchange will stop querying Converters when one Converter recognizes the file. This speeds the recognition process because loading each Converter takes time. This introduces a slight risk of mis-identifying the file, or not recognizing the fact that another Converter might also recognize the file. If Interchange can't seem to recognize a file, do not set Believe first recognized format.

When Only recognize import format is set, Interchange will only query the currently selected Import Format's Converter to see if it can recognize the file. This option gives you the safety and speed of knowing that the Converter could recognize the file, but that no other Converters will be queried.

When Force import is set, Interchange will not attempt to automatically recognize the file. It will attempt to import the object as the currently selected Import format. If the file is not actually in that format, an error can result.

For example, if you are confident that a file is in a certain standard format that should be recognized by Interchange, but isn't, then check Force import, select that format in the Import Format combo box, and begin conversion.

Options / Backup
When Backup files is set, Interchange will preserve any previous versions of files with the same name as the destination file. No files will be deleted or accidentally destroyed by a conversion. This backup scheme preserves the filename extension so that file dialogs in other programs can continue to use simple wildcards to specify files based on a fixed extension.

For example, if you plan to convert the Wavefront file "Apple.obj" to a 3D Studio file "Apple.3DS" and a file with that name already exists, Interchange will rename "Apple.3DS" to "Apple0.3DS" before it creates the new "Apple.3DS" file.

Interchange inserts increasing digits into the filename. In the above example, if you convert the file again, "Apple.3DS" will be renamed to "Apple1.3DS". The older version of the file is "Apple0.3DS". After eleven conversions, there will be files "Apple0.3DS", "Apple1.3DS", etc. up to "Apple10.3DS", the second-most-recent version of the file.

If the filename is already eight characters before the extension, then the digits replace characters in the filename, such as "WALKER15.3DS".

When Backup files is not set, Interchange will destroy any existing file with the same name as the destination file. Use this option with care.

Options / Other
When Remember Selected Files is set, the current list of files to convert will be saved in Interchange's "INI" configuration file. When you re-start Interchange tomorrow, the list of Selected Files will be restored. The list of filename paths is stored in a simple text file called "SELFILES.TXT" in the Interchange directory.