Graphical User Interface

Description

The standard graphical user interface provided by the Viewerdisplaypanel tool is shown in Figure 1.5. Surrounding the actual display area itself are five GUI components: the menu bar at the top, the button bar at the bottom, the tracking bar[s] just above the buttons, the controlbox on the left, and the (currently disabled) ``tapedeck'' control on the right. Applications programmers are able to control which of these components appear on the Viewerdisplaypanel tools that they create, and hence throughout AIPS++, Viewerdisplaypanel tools can appear slightly different from the example given here.

**Figure 1.5:** The Viewerdisplaypanel `tool` graphical user interface
$\begin{figure} \begin{center} \epsfig{file=vdpintro.ps,width=4.1in}\end{center}\end{figure}$

Note: All AIPS++ GUIs have a so-called popup help. Just rest your mouse cursor on top of a GUI element (e.g. a button) and a little frame will appear outlining the funtionality of this element. If you then press and hold down the right mouse button you will get a detailed description. The information given there should be sufficient to let you operate that GUI element.

The menu bar

In , a typical Viewerdisplaypanel tool is shown in all its glory. The menu bar along the top has just three menus:

File, offering selections to create and display new Viewerdisplaypanel tools, access to various managers associated with the Viewer tool, and selections to finish the Viewerdisplaypanel tool itself, and to finish use of the entire Viewer tool.
The File menu is where additional Viewerdisplaypanel tools can be created for use. Multiple Viewerdisplaypanels can be on-screen, and to the best of their ability they will share the available color resources. Three classes of Viewerdisplaypanel can be made: Index panels, on which normal raster maps can be displayed, with pixel intensities mapped to colors from a colormap; and RGB (red-green-blue) and HSV (hue-saturation-value) panels, on which multi-component raster maps can be put together. Viewerdisplaydatas which are set up to use a colormap (eg. 'Rainbow', 'Greyscale', etc.) will only draw when registered on an Index panel. Similarly, Viewerdisplaydatas which are set up to draw to the red, green or blue color channel will only draw themselves on RGB panels. And likewise, Viewerdisplaydatas which are set up to draw to the hue, saturation or value color channel will only draw when registered on HSV panels.
For the RGB and HSV panel types, up to three raster maps can be displayed concurrently, overlaid on each other, with each mapped to a different color component. For example, an optical image could be displayed using the green component, and an X-ray image ``overlaid'' using the red component. In locations of strong X-ray emission and weak optical emission, the map will be predominantly red; weak X-ray emission coincident with strong optical emission will be predominantly green, and in between will be various levels of yellow.
Two sub-classes of Viewerdisplaypanels can be made: non-flashing and most colors panels. The latter provides the most colors available, but with the cost of ugly ``color flashing'' behaviour as the mouse cursor is moved in to and out of the Viewerdisplaypanel window. The former provides generally less colors, but avoids this color flashing, and is generally more appropriate when analysis involving multiple windows is underway.
The menu also gives access to Viewerslicepanel tools in all color modes. Viewerdisplaydata tool with at least three axes can be displayed on these in slice mode. See the documentation for Viewerslicepanel tool for more.
DisplayData, which is where various Viewerdisplaydata tool can be registered (or unregistered) for display on the Viewerdisplaypanel tool. Viewerdisplaydata tool are registered for display by ensuring that their checkbox is lit in this menu. When more than one Viewerdisplaydata tool is available for registration, additional convenience selections are placed at the bottom of the menu, enabling the user to register or unregister all the Viewerdisplaydata tool in the list.
Tools contains a submenu ImageAnalysis ImageAnalysis tools all listen to regions and postions emitted by the region/positioning tool. The Tools menu also contains a Annotations... menu item, which opens the the Annotations GUI.
You can interactively make a region (boxes and polygons) from the display with the cursor. First you select the appropriate button (or icon; box or polygon) from the viewer control buttons arranged vertically along the left-hand side of the display. Whatever mouse button you used to select the icon is now active for creating the region. Either drag out a box, or select vertices of a polygon.
You create the region by double clicking inside of it. When you do this, the Viewerdisplaypanel tool will emit an event called region. See below for a description of that event.
- ImageAnalysis This menu brings up a window with roll-ups for several image analysis operations. Each roll-up has a tab widget for each of the registered Viewerdisplaydatas. You can select the one you want to analyze by pressing the button showing the image name.
  - Statistics This roll-up shows image statistics on the selected image. It listens to event created by the region tools (of the control box. Whenever you emit such a region the fields in this GUI will be updated.
    When you generate an interactive region the statistics are computed only for the current displayed plane of the image. You can extend this spatial region over a range of animation-axis pixels via the Extend check box and by entering a pixel range in the adjacent entry box. For example, entering 10 20 would apply the spatial region to planes 10 through 20 along the animation axis.
    Statistics can also be computed for the full data Full or the current plane Plane as selected with the animator tapedeck. Check the Robust button to also retrieve robust statistics.
    You can also bring up a pgplotter tool to show a statistic histogram by clicking the plot button or alternatively Auto-plot to have that plot updated automatically. The next row of buttons allow you to copy the values shown to the clip board (retrieve with x := dcb.paste()). Auto-copy automatically updates the clip board.
  - Positions The Position rollup consists of a plot button (only if the image has more than 2 dimensions), a copy button, an autocopy switch and position fields to identify the current position of the cursor.
    The position rollup listen's to position events generated by it's parent Viewerdisplaypanel tool (via the crosshair tool) as well as motion events generated by the Viewerdisplaypanel tool from the movement of the mouse over the display area (when position tracking is turned on). When one of these events are received by the position rollup, the current position details are updated.
    You can plot the profile (at the cursor position and along the movie axis) with the button labelled Plot.
    When you submit a region event (see below), the plot will be updated with a new profile. This profile respresents the statistics in the submitted region along the movie axis of the image. The default statistic is mean and can be changed in via the Adjust button near the bottom of the profile window.
    You can copy the position details to the default Clipboard tool (dcb) with the Copy button. This copies a record to the clipboard with the format below. If you prefer, you can autocopy the positions to the Clipboard by checking the Autocopy button. Then, every time you generate a position, a record is automatically copied the Clipboard.
    Format of copied record:
    rec.ddname
    rec.position .pixel .world .numeric .string .intensity .value .mask
    rec.region .pixelblc .pixeltrc .stat
    rec.profile .cs .cs .x .pixel .abs .world .abs .y .data .mask .unit
    The profile can be customized via the Adjust button near the bottom of the profile window. Features such as autoscaling, rest frequency labelling and region profiles are available here.
    You can zoom in the profile window by using the left mouse button using the same method that is used to zoom in the viewer panel. Similarly, an Unzoom button is also available.
  - Regions
    Every time you generate a region, it is also inserted into the region entry widget (a check box flashes to indicate something went in) at the top of the regions rollup (roll it down to see the entry widget !). This enables you to copy it to the default Clipboard tool (dcb) and also paste into it from the default Clipboard tool. When a region is captured, a little indicator light next to the entry widget flashes to indicate something went in. There is also a Show button which prints the bounding box of the region to the logger and shows the regions already generated as a white outline. This button turns into Hide once it is pressed to disable the region drawing.
    It is also possible to accumulate regions, and then make a compound region from all of them. This is done via the Regions rollup; roll it down and look at the row of buttons at the bottom. In this mode, if you have pressed the Show button, the regions are shown individually as they are generated.
    The second button from the left controls the accumulation. If it is labelled Start, when you press it (and its label will then change to Finish), regions are internally accumulated (no region event is emitted and the region is not inserted in the region entry widget). When you have accumulated all the regions you want, you may press Finish. When accumulation mode is active, a check box to the right is lit and the number of regions accumulated displayed. Now a compound region is made from all the regions you accumulated according to the select you make from the left-most menu; you can make a union or intersection. When this region is created, the region event is emitted.
  - Slices Every time you use the polyline tool, a polyline event is generated containing the points of the polyline. These points are used here to
    - Generate an interpolated 1-D slice along the polyline and optionally plot it (use the Plot and Autoplot buttons).
    - For DirectionCoordinates, the distance and position angle between the polyline vertices is computed. If the polyline contains more than two points the sum over all distances and the sum over all angles is shown.
    Use the Copy and Autocopy buttons to transfer the slice, distance and position angle information to the clip board.
  - Summaries This part just shows the same Image.summary would show, wrapped up in a nice gui text area.
Help, which provides selections with which assistance can be obtained on the Viewer tool itself, or more widely within AIPS++.

The button bar

Along the bottom of the Viewerdisplaypanel tool are a few buttons, which are available for commonly executed tasks:

The Adjust... button is used to make adjustments to the way the various Viewerdisplaydata tool draw themselves. Pressing Adjust just once will create adjustment windows for all Viewerdisplaydata tool that are presently registered on the Viewerdisplaypanel tool. Here is a detailed description of the elements of the Adjust GUI.
The Unzoom button is a short-cut to fully unzooming the display--when pressed, the Viewerdisplaypanel tool will re-draw itself displaying as much of the first-registered Viewerdisplaydata tool as is possible.
The Clear button is a short-cut to unregistering all Viewerdisplaydata tool which are presently registered on this Viewerdisplaypanel tool. When pressed, the Viewerdisplaypanel tool will be cleared.
The Print... button is a short-cut to selecting Print... from the File menu, and will bring up the print window for this Viewerdisplaypanel tool, which naturally provides printing operations. For more go to Viewercanvasprintmanager tool.
Finally, the Done button will remove this Viewerdisplaypanel tool from the viewer.

The tracking bar[s]

Separate tracking bars are generated for each Viewerdisplaydata tool registered on the Viewerdisplaypanel tool. They continually report the value and position of the point of the display area under the mouse cursor.

Pressing space bar in the display area will "freeze" the tracking displays or restore them again to continual tracking. Pressing the L key will send the displayed values to the logger. (An even more detailed record may also be sent to the clipboard, by using the Positions rollup under the Tools/ImageAnalysis menu item).

Note that if you have "click-to-focus" set in your windowing system, you may need to click on the displaypanel's window before it will recognize the key presses above. This can be confusing, since the tracking bar[s] will respond to mouse movement in any case.

The control box

The control box (on the left hand side of most Viewerdisplaypanel tools) provides a more convenient way to access the various controls available on Viewerdisplaypanel tools. Clicking on a button will assign that control to the mouse button which was used to click, over-riding any previous assignment to that mouse button.

For most tools the following actions apply:

``Esc'' key cancels the tool.
``Double click'' of the button assigned to the tool executes it (eg. with regions it sends out an event).
``Handles'' (little boxes on the edges) can be used to resize the tool.

From the top button downwards, the controls are:

Zooming: The top-most button, depicting a magnifying glass with a plus sign inside, is the zoom control button. Zooming is accomplished by pressing down the selected mouse button at the start point, dragging the mouse away from that point, and releasing the selected mouse button when the zoom box encloses the desired zoom area. Once the button is released, the zoom rectangle can be moved by clicking inside it with the selected mouse button and dragging it around, and resized by selecting one of the handles at the corners and dragging.
To zoom in, simply double click with the selected button inside the rectangle, and when the Viewerdisplaypanel tool is re-drawn, the area enclosed by the rectangle will be expanded to fill the Viewerdisplaypanel tool, in as much as other constraints allow this. Double clicking outside the rectangle, will result in a zoom out, whereby the previous full view will be scaled down to fit within the rectangle, in as much as other constraints allow this.
Panning: The next button down, whose icon is the outline of a hand, is the panning control button. Panning is accomplished by pressing down the selected mouse button at the point you wish to move, dragging the mouse to the position where you want the first point moved to, and releasing the selected mouse button.
Note: The arrow keys, Page Up, Page Down, Home and End keys, and scroll wheel (if any) can also be used to scroll through your data once you have zoomed in. For these to work, the mouse must be over the display panel drawing area, but no mouse tool need be active. All but the left and right arrows apply only to the vertical direction. However, you can use the Crtl key in conjunction with the arrows to move one page at a time in any direction.
Stretch-shift colormap fiddling:
Brightness-contrast colormap fiddling:
Positioning: The fifth control is a crosshair icon, which enables the user to place a crosshair marker on the Viewerdisplaypanel to indicate a position. Depending on the context, the emitted positions may be used, for example, to display image spectral profiles or flag measurement set data. After selecting a mouse button for the crosshair, click on the Viewerdisplaypanel to place it, and drag to move it around. Double-click is not needed with this control; the position is emitted whenever the crosshair's assigned mouse button is pressed or the crosshair is moved. Note: position selection is quite different from position tracking.
Rectangle and Polygon region drawing: Rectangular and polygonal regions can easily be constructed. The rectangle region is generated exactly the same way as the zoom rectangle, and is emitted by double clicking within the rectangle. Polygon regions can be constructed by progressively clicking the selected mouse button at the desired location of each vertex, and clicking in the same location twice to complete the polygon. Once constructed, it can be moved by dragging inside the polygon, and reshaped by dragging the various handles at the vertices. Double click within the polygon to emit the polygonal region. Compound image regions can be built up using these controls. The rectangular control can also be used to specify areas to be flagged in measurement sets.
Polyline drawing: A polyline can be constructed with this tool. This tool is almost identical to the polygon region tool. Create the points by clicking at the positions wanted and the double-click to finish the line. this generates a polyline event.

The animation tapedeck

In its 'Normal' mode, the tapedeck-style controls down the right-hand side of most Display Panels provide basic movement between image planes, along a selected third dimension of the displaydatas. This set of buttons will only be enabled when the first-registered displaydata reports that it has more than one plane along the 'Z axis' specified in its 'Adjust' panel. In the most common case the animator controls the frequency channel being viewed. From the top down, the tape deck controls allow the user to:

rewind to the start of the sequence (i.e. the first plane)
step backwards by one plane
play backwards, or repetitively step backwards
stop any current play
play forwards, or repetitively step forwards
step forwards by one plane
fast forward to the end of the sequence

Below the tapedack buttons is an editable text box indicating the current frame number and a sunken label showing the total number of frames. One can type a channel number into the current frame box to jump to that channel, for example, when 'Frequency' is on the 'Z axis'.

Below these is a right-arrow button; pressing it will display a popup frame containing sliders for setting the animation speed and the number of frames to skip when playing animations.

Below all these controls is a pair of radio buttons selecting animator mode: either 'Normal' (the default mode described above) or 'Blink'. In 'Blink' mode, when more than one raster image is registered on the Display Panel, the tapedeck will control which one is being displayed at the moment. The images registered should cover the same portion of the sky, using the same coordinate projection. Several images can also be displayed side-by-side in this mode, with the same zoom applied to all. For details on operating the Display Panel in this mode, see the Display section of the AIPS++ Cookbook, vol. 1.

Next: Events Up: viewerdisplaypanel - Tool Previous: General description Contents Index