Example: Structure Data in a Table Widget
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.
This example is included in the file table_widget_example2.pro
in the examples/doc/widgets
subdirectory of the IDL distribution. Run this example procedure by entering table_widget_example2
at the IDL command prompt or view the file in an IDL Editor window by entering .EDIT table_widget_example2.pro
. 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:
- By default, column and row titles will contain the index of the column or row. To remove either column or row titles entirely, set the value of the COLUMN_LABELS or ROW_LABELS keyword to an empty string (
''
). - Setting the width of the row-title column of the row-major table requires us to select column
-1
using the USE_TABLE_SELECT keyword.