Annotation Widget The Annotation widget allows you to interactively annotate images and plots with text and drawings. Drawing objects include lines, arrows, polygons, rectangles, circles, and ellipses. Annotation files can be saved and restored, and annotated displays can be written to TIFF, PNG, or PostScript files. The Annotation widget will work on any IDL graphics window or draw widget. Using the Annotation Widget Before calling the Annotation widget, plot or display your data in an IDL graphics window or draw widget. Unless you specify otherwise (using the DRAWABLE or WINDOW keywords to ANNOTATE), annotations will be made in the current graphics window. MODES The Annotation widget has three modes of operation: Draw, Edit, and Select. - Draw Mode Allows you to design and create new annotation objects. - Edit Mode Allows you to move, resize, or otherwise change existing annotation objects. In Edit Mode, "handles" appear on the annotation object. - Select Mode Allows you to choose an existing annotation object for editing. Select an object by clicking the left mouse button in the center of the object. When you release the mouse button, the object's handles will appear and the Annotation widget will switch to Edit Mode. Select a mode by clicking on the appropriate Mode Button. You can also switch between Draw Mode and Edit Mode by clicking the middle mouse button. SAVING OBJECTS Once you have created an annotation object, you must save it before going on to create another. Save objects either by clicking on the "Save" button or by clicking the right mouse button when the annotation object to be saved is selected. If the object is not saved and you switch from one type of object to another, the unsaved object will be removed from the annotation. When the object has been saved, the mode switches automatically from "Edit" to "Draw". To change a saved object, choose Select Mode, select the object and edit it. Note that once an object is selected, it is removed from the "saved" list and thus must be saved again after modification. ANNOTATION OBJECTS The Annotation widget supports five types of annotation objects: Text, Lines and Arrows, Polygons and Polylines, Ellipses, and Rectangles. The different objects are represented by a row of bitmap buttons in the Annotation widget. To select a type of annotation, click on the appropriate button. The lower portion of the Annotation widget changes to present the controls available for that type of object. NOTE: If you switch from one type of object to another before saving an object, the unsaved object will be deleted. - Text To create a text annotation, enter the text in the field labelled "Text", then click with the left mouse button in the image. Your annotation text appears and the mode switches immediately to "Edit." Resize or rotate the annotation text using the mouse by clicking on one of the handles and dragging, or adjust the "Size" and "Orientation" sliders. Adjust the thickness of the text line strokes using the "Thickness" slider. Use the "Font" selection widget to select a font. Text can be aligned to the left, right, or center by selecting the appropriate button. - Lines and Arrows To create a line or arrow, click with the left mouse button and drag the mouse until you have created the desired line. Click on the "Arrow" button to create an arrow or on "Solid Arrow" to create an arrow with a filled triangle as its head. Adjust the size of the arrowhead by moving the "Head Size" slider. - Polygons and Polylines The Polygon/Polyline tool has three sub-modes: - Draw: (the initial mode). Drag or click the left mouse button to add points to the object, connecting the most recent point to the mouse position. - Edit: Select and move a vertex or point by clicking and dragging with the left mouse button. - Delete: Remove the vertex or point closest to the cursor position when the left mouse button is pressed. Polygons can be unfilled, filled with a solid color, or filled with parallel lines by selecting the appropriate button next to the "Fill" label. If an object is filled with lines, the angle of the lines and the spacing between them can be adjusted using the "Line Angle" and "Line Spacing" sliders. Choosing "Spline" next to the "Interpolation" label will produce objects constructed of smooth curves rather than polygons. - Ellipses To create an ellipse, click with the left mouse button at the point you wish to be the center of the ellipse and drag until the ellipse is the desired size. Adjust the eccentricity of the ellipse using the "Eccentricity" slider. Ellipses can be unfilled, filled with a solid color, or filled with parallel lines by selecting the appropriate button next to the "Fill" label. If an object is filled with lines, the angle of the lines and the spacing between them can be adjusted using the "Line Angle" and "Line Spacing" sliders. - Rectangles To create a rectangle, click with the left mouse button at the point you wish to be the upper left corner of the rectangle and drag until the rectangle is the desired size. Rectangles can be unfilled, filled with a solid color, or filled with parallel lines by selecting the appropriate button next to the "Fill" label. If an object is filled with lines, the angle of the lines and the spacing between them can be adjusted using the "Line Angle" and "Line Spacing" sliders. COLOR The color of any annotation object can be changed by selecting the object and picking a new color from the Annotation widget color bar. LINESTYLE You can adjust the thickness of lines and text using the "Thickness" slider. You can change the style of lines and shapes using the "Linestyle" selection widget. Note that fill lines are not affected by the choice of line style. CURSOR POSITION The current cursor position with the graphics window is shown (in pixel coordinates) in the window in the center of the Annotation widget. THE FILE MENU The File menu (at the upper left-hand corner of the Annotation widget) contains the following items: - Load Load a saved annotation file into the current graphics window. A file-selection dialog allows you to select a previously-saved annotation file. When restoring objects, be sure that the window you are loading into has the same geometry as did the window from which the objects were saved. - Save Save the current annotations in a file. If an annotation file has not yet been opened or specified using the "Save As" menu option, the file will be named "annotate.dat" and placed in the current directory. Note that only the annotations, and not the underlying image or plot, are saved. - Save As Save the current annotations in a file. A file-selection dialog allows you to name the resulting file. Annotation files have the suffix ".dat" by default. Note that only the annotations, and not the underlying image or plot, are saved. - Write PostScript Create a PostScript file of your annotations. This menu choice reveals a submenu allowing you to choose "Everything" or "Objects only". Choose "Everything" to output the contents of the graphics window (your original plot or image) as a bitmap, and the annotation objects as PostScript drawing commands. This creates a single file and provides the best resolution. Choose "Objects only" to save only the annotation objects. Use this mode to combine the annotations with PostScript commands that have already been output to obtain the highest resolution. To use this procedure, take the following steps: 1) Open the PostScript device and create the plot over which you wish your annotations to appear. Be sure that it has the same aspect ratio as does you drawing window. For example, if you have a 640 x 512 drawing window, and you wish to make your PostScript drawing 4 inches wide, the PostScript height or YSIZE must be set to 4.0 * 512 / 640 = 3.2 inches, e.g. DEVICE, XSIZE=4, YSIZE=3.2, /INCHES. 2) Select the window system as your plot device, and re-execute the commands that produced the background you wish to annotate. 3) Call ANNOTATE, make your annotations, and then use this option to output the PostScript. The PostScript device is not closed upon completion, as it is with the other two PostScript output options. - Export Bitmap Convert the entire contents of the graphics window (image and annotations) to a bitmap and output in the format you choose. The options available are PNG, PostScript, and TIFF. - Clear Clear the graphics window of all annotations. - Exit Exit the Annotation widget. OPTIONS BUTTON Click on the "Options" button to select various types of PostScript output: - Standalone or Encapsulated (to be inserted into another document). - Monochrome or Color, always use Monochrome unless you have a color PostScript printer. - Portrait or Landscape. The width parameter scales the output size. The height of the output drawing is scaled from the width to retain the same aspect ratio as the original drawing window. CALLING THE ANNOTATION WIDGET For information on how to call the Annotation widget from your program, see ANNOTATE in the IDL Reference Guide or the IDL on-line help.