- XmNfontType
Specifies the type of the Rendition font object. For CTL, the value of this resource must be the XmFONT_IS_XOC value. If the value does not match, then the XmNlayoutAttrObject and XmNlayoutModifier resources are ignored.
When the value of this resource is XmFont_IS_XOC, and if the XmNfont resource is not specified, then at create time the value of the XmNfontName resource is converted into an XOC object in either the locale specified by the XmNlayoutAttrObject resource or the current locale. Furthermore, the value of the XmNlayoutModifier resource is passed through to any layout object associated with the XOC.
- XmNlayoutAttrObject
Specifies the layout AttrObject argument. This resource is used to create the layout object associated with the XOC associated with this XmRendition. Refer to the layout services m_create_layout() specification for the syntax and semantics of this string. See the description of XmNfontType for an explanation of the interaction between the Layout Modifier Orientation output value and the XmNlayoutDirection widget resource.
- XmNlayoutModifier
Specifies the layout values to be passed through to the layout object used with the XOC for this XmRendition. For the syntax and semantics of this string, see CAE Specification.
Setting this resource using XmRendition{Retrieve,Update} causes the string to be passed through to the layout object associated with the XOC associated with this rendition. This is the mechanism for configuring layout services dynamically. Unpredictable behavior can result if the Orientation, Context, TypeOfText, TextShaping, or ShapeCharset are changed.
Additional Layout Behavior
The XmNlayoutModifier affects the layout behavior of the text associated with the XmRendition. For example, if the layout default treatment of numerals is NUMERALS_NOMINAL, the user can change to NUMERALS_NATIONAL by setting XmNlayoutModifier to @ls numerals=nominal:national, or @ls numerals=:national.
The layout values can be classified into the following groups:
Encoding description-TypeOfText, TextShaping, ShapeCharset (and locale codeset)
TypeOfText is essentially segment ordering and can be illustrated with opaque blocks. Modifying these values dynamically, through the rendition object, is not usually meaningful, and is almost certain to result in unpredictable behavior.
Layout behavior-Orientation, Context, ImplicitAlg, Swapping, and Numerals. Orientation and Context should not be modified dynamically. You can safely modify ImplicitAlg, Swapping, and Numerals.
XmText and XmTextField
Xm CTL extends XmText and XmTextField by adding a parallel set of movement and deletion actions that operate visually, patterned after the Motif 2.0 CSText widget. The standard Motif 2.1 Text and TextField do not distinguish between logical and physical order: next and forward mean "to the right," while previous and backward mean "to the left." CSText, however, makes the proper distinction and defines a new set of actions with strictly physical names (for example, left-character(), delete-right-word(), and so on). All of these action routines are defined to be sensitive to the XmNlayoutDirection of the widget and to call the appropriate next- or previous- action. The Xm CTL extensions are slightly more complex than the CSText extensions. The Xm CTL extensions are sensitive not to the global orientation of the widget, but to the specific directionality of the physical characters surrounding the cursor, as determined by the pseudo-XOC, including neutral stabilization.
There is also a new resource to control selection policy, to provide a rendition tag, and to control alignment.
The set of new Xm CTL actions is roughly the cross product of {Move,Delete,Kill} by {Left,Right} by {Character,Word}, and is listed below.
Table 6-2 New Resources in Xm CTL
Name | Class/Type | Access | Default Value |
|---|---|---|---|
XmNrenditionTag | XmCRenditionTag/XmRString | CSG | XmFONTLIST_DEFAULT_TAG |
XmNalignment | XmCAlignment/XmRAlignment | CSG | XmALIGNMENT_BEGINNING |
XmNeditPolicy | XmCEditPolicy/XmREditPolicy | CSG | XmEDIT_LOGICAL |
- XmNrenditionTag
Specifies the rendition tag of the XmRendition that is in the XmNrenderTable resource, used for this widget.
- XmNalignment
Specifies the text alignment used in the widget. Only XmALIGNMENT_END and XmALIGNMENT_CENTER are supported.
- XmNeditPolicy
Specifies the editing policy used for the widget, either XmEDIT_LOGICAL or XmEDIT_VISUAL. In the case of XmEDIT_VISUAL, selection, cursor movement, and deletion are in a visual style. Setting this resource also changes the translations for the standard keyboard movement and deletion events either to the new "visual" actions list or to the existing logical actions.
Character Orientation Action Routines
The forward-cell() and backward-cell() actions query the orientation of the character in the direction specified. If the direction is left-to-right, they call the corresponding next-/forward- or previous-/backward- variants:
Character Orientation Additional Behavior
The actions determine the orientation of characters by using the Layout Services transformation OutToInp and Property buffers (for the nesting level). The widget's behavior is therefore dependent on the locale-specific transformation. If the information in the OutToInp or, especially, Property buffers is inaccurate, the widget might behave unexpectedly. Moreover, as the locale-specific modules fall outside of the scope of this specification, bi-directional editing behavior can differ from platform to platform for the same text, application, resource values, and LayoutObject configuration.
The visual mode actions result in a display of cell-based behavior. The logical mode actions result in logical character-based behavior. For example, the delete-right-character() operation deletes the input buffer characters that correspond to the display cell. That is, one input buffer character whole LayoutObject transformation "property" byte "new cell indicator" is 1, and all of the succeeding characters whose "new cell indicator" [For more information on the Property buffer, see the specification for m_transform_layout() in CAE Specification.] is 0.
Similarly, for backward-character(), the insertion point is moved backward one character in the input buffer, and the cursor is redrawn at the visual location corresponding to the associated output buffer character. This means that several keystrokes are required to move across a composite display cell; the cursor does not actually change display location as the insertion point moves across input buffer characters whose "new cell indicator" is 0 (that is, diacritics or ligature fragments).
This means that deletion operates either from the logical/input buffer side, or from the display cell level of the physical/output side. There is no mode for a strict, physical character-by-character deletion, since there is no one-to-one correspondence between the input and output buffers. A given physical character can represent only a fragment of a logical character, for example.
XmText Action Routines
The follwoing list describes the XmText action routines.
- left-character(extend)
If the XmNeditPolicy is XmEDIT_LOGICAL and is called without arguments, the insertion cursor moves back logically by a character. If the insertion cursor is at the beginning of the line, the insertion cursor moves to the logical last character of the previous line, if one exists. Otherwise, the insertion cursor position doesn't change.
If the XmNeditPolicy is XmEDIT_VISUAL, then the cursor moves to the left of the cursor position. If the insertion cursor is at the beginning of the line, then it moves to the end character of the previous line, if one exists.
If left-character() is called with an extend argument, the insertion cursor moves, as in the case of no argument, and extends the current selection.
The left-character() action produces calls to the XmNmotionVerifyCallback procedures with the reason value XmCR_MOVING_INSERT_CURSOR. If called with an extend argument, this action can produce calls to the XmNgainPrimaryCallback procedures. See the callback description in the Motif Programmer's Reference for more information.
- right-character(extend)
If the XmNeditPolicy is XmEDIT_LOGICAL and is called without any arguments, it moves the insertion cursor logically forward by a character. If the insertion cursor is at the logical end of the line, it moves the insertion cursor to the logical starting of the next line, if one exists.
If the XmNeditPolicy is XmEDIT_VISUAL, then the cursor moves to the right of the cursor position. If the insertion cursor is at the end of the line, it moves the insertion cursor to the starting of the next line, if one exists.
If called with an argument of extend, it moves the insertion cursor, as in the case of no argument, and extends the current selection.
The right-character() action produces calls to the XmNmotionVerifyCallback procedures with the reason value XmCR_MOVING_INSERT_CURSOR. If called with extend argument, this can produce calls to the XmNgainPrimaryCallback procedures. See the callback description in the Motif Programmer's Reference for more information.
- right-word(extend)
If the XmNeditPolicy is XmEDIT_LOGICAL and is called without any arguments, it moves the insertion cursor to the logical starting of the logical succeeding word, if one exists; otherwise, it moves to the logical end of the current word. If the insertion cursor is at the logical end of the line or in the logical last word of the line, it moves the cursor to the logical first word in the next line, if one exists; otherwise, it moves to the logical end of the current word.
If the XmNeditPolicy is XmEDIT_VISUAL and is called without arguments, it moves the insertion cursor to the first nonwhite space character after the first white space character to the right or after the end of the line.
If called with an argument of extend, it moves the insertion cursor, as in the case of no argument, and extends the current selection.
The left-word() action produces calls to the XmNmotionVerifyCallback procedures with the reason value XmCR_MOVING_INSERT_CURSOR. If called with extend argument, this can produce calls to the XmNgainPrimaryCallback procedures. See the callback description in the Motif Programmer's Reference for more information.
- delete-left-character()
If the XmNeditPolicy is XmEDIT_LOGICAL, it is equivalent to delete-previous-char(). If the XmNeditPolicy is XmEDIT_VISUAL, then in normal mode, if there is a non-null selection, it deletes the selection; otherwise it deletes the character left of the insertion cursor. In add mode, if there is a non-null selection, the cursor is not disjointed from the selection and XmNpendingDelete is set to True, it deletes the selection; otherwise, it deletes the character left of the insertion cursor. This can impact the selection.
The delete-left-character() action produces calls to the XmNmodifyVerifyCallback procedures with reason value XmCR_MODIFYING_TEXT_VALUE and the XmNvalueChangedCallback procedures with reason value XmCR_VALUE_CHANGED.
- delete-right-character()
If the XmNeditPolicy is XmEDIT_VISUAL, it is equivalent to delete-next-character(). If the XmNeditPolicy is XmEDIT_VISUAL, then in normal mode, if there is a non-null selection, it deletes the selection; otherwise, it deletes the character right of the insertion cursor. In add mode, if there is a non-null selection and the cursor is not disjointed from the selection, the XmNpendingDelete is set to True and the selection is deleted; otherwise, the character right of the insertion cursor is deleted. This can impact the selection.
The delete-right-character() action produces calls to the XmNmodifyVerify-Callback procedures with reason value XmCR_MODIFYING_TEXT_VALUE, and the XmNvalue-ChangedCallback procedures with reason value XmCR_VALUE_CHANGED.
A few cell-based routines are implemented to support character composition, ligatures, and diacritics. In other words, two or more characters might be represented by a single glyph occupying one presentation cell.
The XmText cell action routines are as follows:
- backward-cell(extend)
Moves the insertion cursor back one cell. If the XmNeditPolicy is XmEDIT_LOGICAL, then the insertion cursor is moved to the start of the cell that precedes the current cell logically, if one exists; otherwise, it moves to the start of the current cell.
If the XmNeditPolicy is XmEDIT_VISUAL, then the cursor moves to the start of cell to the left of the cursor, if one exists. The prev-cell() action produces calls to the XmNmotionVerifyCallback procedures with the reason value XmCR_MOVING_INSERT_CURSOR. If called with an extend argument, this can produce calls to the XmNgainPrimaryCallback procedures. See the callback description in the Motif Programmer's Reference for more information.
- forward-cell(extend)
Moves the insertion cursor to the start of the logical next cell, if one exists; otherwise it moves it to the end of the cell. If the XmNeditPolicy is XmEDIT_LOGICAL, then the cursor moves forward one cell.
If the XmNeditPolicy is XmEDIT_VISUAL, then the cursor moves to the start of the cell to the right of the cursor position, if one exists; otherwise, it moves to the end of the current cell. The forward-cell() action produces calls to the XmNmotionVerifyCallback procedures with the reason value XmCR_MOVING_INSERT_CURSOR. If called with an extend argument, this can produce calls to the XmNgainPrimaryCallback procedures. See the callback description in the Motif Programmer's Reference for more information.