Smalltalk/X Webserver

Documentation of class 'DataSetColumn':

Class: DataSetColumn

Inheritance
Description
Class protocol
Instance protocol

Inheritance:

   Object
   |
   +--DataSetColumn

Package:: stx:libwidg2

Category:: Views-DataSet

Version:: rev: 1.175 date: 2022/03/05 12:44:14; user: cg; file: DataSetColumn.st directory: libwidg2; module: stx stc-classLibrary: libwidg2

Description:

represent one single column description of a DataSetView

[Instance variables:]

    columnNumber    <Integer>               sequence number (into list of columns)

    dataSet         <DSVColumnView>         the view it belongs to

    width           <Integer>               width of column

    description     <DataSetColumnSpec>     the column description (a spec)

    buttonExtent    <Point>                 extent of drawable form

    rendererType    <Type>                  renderer type (cached value from
                                            the column specification).

    backgroundColor <Color or nil>          background color of all cells or nil
                                            (nil: use default background color).

    foregroundColor <Color or nil>          foreground color of all cells or nil
                                            (nil: use default foreground color).

    columnAlignment <Symbol>                align text/icon #left #right or #center
                                            in row (by default: #left).

    label           <label/icon or nil>     label resolved by the builder shown
                                            in the column description field.

    readSelector    <Symbol>                cached readSelector (from the spec)

    columnAdaptor   <nil or any>            if non-nil, that one is asked (via
                                            read-writeSelectors to extract a column
                                            from a row object.
                                            If nil, the row object is used itself.

    showColSeparator <Boolean>              true: vertical separators are enabled;
                                            separator between columns

    showRowSeparator <Boolean>              true: horizontal separators are enabled;
                                            separator between rows

    rowSeparatorSelector <Selector or nil>  access specific showRowSeparator state
                                            for a cell

[from description:]
    fgSelector      <Selector or nil>       access specific foreground color for
                                            a cell

    bgSelector      <Selector or nil>       access specific background color for
                                            a cell

    numberOfRowsProbedForColumnSize         the number of rows which are queries
                            <Integer>       in order to compute the columns width.
                                            (for scrollBar/col width computation)
                                            Notice, if it's expensive to fetch rows
                                            (dataBase apps), this should be small.
                                            Default:15

copyrightCOPYRIGHT (c) 1997 by Claus Gittinger / eXept Software AG
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Class protocol:

constants

editorType_CheckToggle
editorType_ComboBox
editorType_ComboList
editorType_InputField
editorType_None
editorType_PopUpList
editorType_RadioButton
editorType_Text
editorType_rowSelector

initialization

initialize: (comment from inherited method)
called only once - initialize signals

utilities

shortenedStringFor: aString on: aGC maxWidth: maxWidth: common code to shorten a string; used in both the DSV label- and column Views,
if the string is too long for the column
shortenedStringFor: aString on: aGC maxWidth: maxWidth shortenedAtLeft: shortenedAtLeft: common code to shorten a string; used in both the DSV label- and column Views,
if the string is too long for the column

Instance protocol:

accessing

activeHelpText: get the active helpText or nil
activeHelpTextForLabel: get the active helpText for the label or nil
activeHelpTextForRow: rowNr: get the active helpText or nil
at: aRowNr: get the value of the cell at the row index, aRowNr
at: aRowNr put: something: set the value of the cell at the row index, aRowNr
columnAdaptor: If non-nil, messages to fetch/store columns from a model-list's element
will be sent to the adapter (i.e. it can map or compute values).
Use #yourself to let the application itself access the columns.
Use nil or leave empty, to have messages been sent directly to the row element.
The per-column getter/setter messages are specified in the columnSpecification.
columnAdaptor: anAdapter: If non-nil, messages to fetch/store columns from a model-list's element
will be sent to the adapter (i.e. it can map or compute values).
Use #yourself to let the application itself access the columns.
Use nil or leave empty, to have messages been sent directly to the row element.
The per-column getter/setter messages are specified in the columnSpecification.
columnNumber
description: returns the column spec
doubleClickSelector: selector which is sent without argument on the cell when double clicked
doubleClickedSelector: obsolete: use: #doubleClickSelector
However: do not remove: it may still be found in many UI-specs
label: get the label assigned to the column
longStringCompression
longStringCompression: aBoolean
longStringCompressionAtLeft
rendererType: returns my renderer type

accessing-color & font

backgroundColor: returns the background color or nil
backgroundColor: aColor
backgroundColorAt: aRowNr: returns the background color for a row at list index a rowNr
backgroundColorFor: aRow at: aRowNr: return the background color for a row at list index a rowNr
colorFor: aRow at: aRowNr descriptionSelector: descriptionSelector descriptionColor: descriptionColor dataSetDefaultColor: dataSetColor: common code for returning a color for a row at list index a rowNr, asking both description and dataSet as fallBack
foregroundColor: returns the foreground color or nil
foregroundColor: aColor
foregroundColorFor: aRow at: aRowNr: returns the foreground color for a row at list index a rowNr
selectedBackgroundColorFor: aRow at: aRowNr: returns the selected background color for a row at list index a rowNr
selectedForegroundColorFor: aRow at: aRowNr: returns the selected foreground color for a row at list index a rowNr
selectedFrameColorFor: aRow at: aRowNr: returns the selected frame color for a row at list index a rowNr

accessing-dimension

minWidth: get the minimum width required by the column
minimumRequiredWidth: returns the minimum required width
setDescWidth: aWidth: set a fixed width
setWidth: pixels
width: returns the width in pixels
Warning:
only the first numberOfRowsProbedForColumnSize are probed,
in case the access is expensive (dataBase apps)
If the descriptor defines a width, that is used, and the items
are not probed at all.
width: aWidth

drawing

drawLabel: aLabelToDraw atX: xLeft y: yTop: draw aLabelToDraw; handle columnAlignment
drawLabelsAtX: xLeft y: yTop h: h from: start to: stop: redraw labels from start to stop
drawRendererInRow: rowNr x: xLeft y: y width: cellWidth value: cellValue
drawSeparatorsAtX: xLeft y: yTop h: h from: start to: stop: redraw separators for cells between start and stop
invalidate: invalidate width of column; forces a recomputation
redrawX: xLeft y: yTop h: h from: start to: stop: redraw all rows between start and stop
shownValueForRow: aRowOrNil rowNr: aRowNr: cannot remember what this was used for ...

editing

editorForRowAt: aRowNr: creates the editor for the row in a view and returns an editorAndModel, or nil

event handling

doesNotUnderstand: aMessage: (comment from inherited method)
this message is sent by the runtime system (VM) when
a message is not understood by some object (i.e. there
is no method for that selector). The original message has
been packed into aMessage (i.e. the receiver, selector and
any arguments) and the original receiver is then sent the
#doesNotUnderstand: message.
Here, we raise another signal which usually enters the debugger.
You can of course redefine #doesNotUnderstand: in your classes
to implement message delegation,
or handle the MessageNotUnderstood exception gracefully.

grow & shrink

growWidth: n: grow the width for n pixels

initialization

on: aDSVColumnView description: aDescription columnNumber: aNumber label: aLabel: instance creation; set attributes dependent on the description

private

extractColFromRow: aRow rowNr: rowNr: I don't use valueWithOptionalArgument:and:and:and: here, to make better use of inline caches...
storeCol: newValueArg inRow: aRow

queries

canResize
canSelect: aRowNr: returns true if the cell in column is selectable.
(possibly calls the selectSelector, if any)
choicesFor: aRow at: aRowNr
containsText: returns true if text might exist
doubleClickOn: aRowNr
hasChoices: aRowNr
hasPotentialNonConstantBackground
hasRelativeWidth: returns true if width is relative
hasRowSeparatorAt: rowNumber
heightOfHighestRow: returns the height of the highest row in pixels.
Warning:
only the first numberOfRowsProbedForColumnSize are probed,
in case the access is expensive (dataBase apps)
If the descriptor defines a height, that is used, and the items are not probed at all.
If the descriptor's height is -1 or #fontHeight, that is used.
If the descriptor's height is #heightOfFirstRow, only the first columns height is probed.
heightOfLabel: aLabel: returns the height of the label
isResizeable: returns true if the row is resizeable
isRowVisible: rowNr
isSortable
showColSeparator: returns true if column separator is on
showSelectionHighLighted: returns true if selection is highLighted
translatedChoicesFor: aRow at: aRowNr
widthOfLabel: aLabel: returns the width of the label

searching

findRowNrStartingWithChar: aChar start: start stop: stop: find the first row starting at start to stop, which drawable label
starts with the character, aChar. The index of the detected row is
returned or if no row is found 0.

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