Previous User Interface Programming: Using Table Widgets Next

Example: Structure Data

The following procedures build a simple application that displays the same structure data in two table widgets; one in row-major format and one in column-major format.


Example Code
This example is included in the file table_widget_example2.pro in the examples/doc/widgets subdirectory of the IDL distribution. You can either open the file in an IDL editor window and compile and run the code using items on the Run menu, or simply enter
   table_widget_example2
at the IDL command prompt. See Running the Example Code if IDL does not run the program as expected.

; Event-handler routine for 'Quit' button  
PRO table_widget_example2_quit_event, ev  
  WIDGET_CONTROL, ev.TOP, /DESTROY  
END  
  
; Widget creation routine.  
PRO table_widget_example2  
  
  ; Create some structure data.  
  d0={planet:'Mercury', orbit:0.387, radius:2439, moons:0}  
  d1={planet:'Venus', orbit:0.723, radius:6052, moons:0}  
  d2={planet:'Earth', orbit:1.0, radius:6378, moons:1}  
  d3={planet:'Mars', orbit:1.524, radius:3397, moons:2}  
  
  ; Combine structure data into a vector of structures.  
  data = [d0, d1, d2, d3]  
  
  ; Create labels for the rows or columns of the table.  
  labels = ['Planet', 'Orbit Radius (AU)', 'Radius (km)', 'Moons']  
  
  ; To make sure the table looks nice on all platforms,  
  ; set all column widths to the width of the longest string  
  ; that can be a header.  
  max_strlen = strlen('Orbit Radius (AU)')  
  maxwidth = max_strlen * !d.x_ch_size + 6   ; ... + 6 for padding  
  
  ; Create base widget, two tables (column- and row-major,  
  ; respectively), and 'Quit' button.  
  base = WIDGET_BASE(/COLUMN)  
  table1 = WIDGET_TABLE(base, VALUE=data, /COLUMN_MAJOR, $  
    ROW_LABELS=labels, COLUMN_LABELS='', $  
    COLUMN_WIDTHS=maxwidth, /RESIZEABLE_COLUMNS)  
  table2 = WIDGET_TABLE(base, VALUE=data, /ROW_MAJOR, $  
    ROW_LABELS='', COLUMN_LABELS=labels, /RESIZEABLE_COLUMNS)  
  b_quit = WIDGET_BUTTON(base, VALUE='Quit', $  
    EVENT_PRO='table_widget_example2_quit_event')  
  
  ; Realize the widgets.  
  WIDGET_CONTROL, base, /REALIZE  
  
  ; Retrieve the widths of the columns of the first table.  
  ; Note that we must realize the widgets before retrieving  
  ; this value.  
  col_widths = WIDGET_INFO(table1, /COLUMN_WIDTHS)  
  
  ; We need the following trick to get the first column (which is  
  ; a header column in our first table) to reset to the width of  
  ; our data columns. The initial call to keyword COLUMN_WIDTHS  
  ; above only set the data column widths.  
  WIDGET_CONTROL, table1, COLUMN_WIDTHS=col_widths[0], $  
    USE_TABLE_SELECT=[-1,-1,3,3]  
  ; This call gives table 2 the same cell dimensions as table 1  
  WIDGET_CONTROL, table2, COLUMN_WIDTHS=col_widths[0], $  
    USE_TABLE_SELECT=[-1,-1,3,3]  
  
  ; Call XMANAGER to manage the widgets.  
  XMANAGER, 'table_widget_example2', base  
  
END

The following things about this example are worth noting:

  IDL Online Help (March 06, 2007)