XmText, XmTextField

Description

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," and "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 CSText's in that they 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.

New Resources

The following new resources are added to XmText and XmTextField:

XmNrenditionTag

Specifies the rendition tag of the XmRendition (in the XmNrenderTable resource) to be used for this widget.

XmNalignment

Specifies the text alignment to be used in the widget. Only XmALIGNMENT_END and XmALIGNMENT_CENTER are supported.

XmNeditPolicy

Specifies the editing policy to be 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 below or to the existing logical actions.

Action Routines

All of the actions in the following list 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.

• delete-left-character()

• delete-left-word()

• delete-right-character()

• delete-right-word()

• kill-left-character()

• kill-left-word()

• kill-right-character()

• kill-right-word()

• left-character()

• left-word()

• prev-cell()

• right-character()

• right-word()

• forward-cell()

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 may behave unexpectedly. Moreover, as the locale-specific modules fall outside of the scope of this specification, bi-directional editing behavior may differ from platform to platform for the same text, application, resource values, and LayoutObject configuration.

The visual mode actions result in display 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 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 may represent only a fragment of a logical character, for example.

Action Routines

The XmText action routines are as follows:

left-character(extend)

If the XmNeditPolicy is XmEDIT_LOGICAL and is called without arguments, it moves the insertion cursor back logically by a character. If the insertion cursor is at the beginning of the line, it moves the insertion cursor 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 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 it is called with an extend argument, it moves the insertion cursor 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 may produce calls to the XmNgainPrimaryCallback procedures. See the callback description in the Motif Programmer's Reference for more information.

left-word(extend)

If the XmNeditPolicy is XmEDIT_LOGICAL and is called without any arguments, and the insertion cursor is at the logical starting of the word, it moves the insertion cursor to the logical starting of the logical preceding word, if one exists, otherwise the insertion cursor position doesn't change. If the insertion cursor is in the word but not at the logical start of the word, it moves the insertion cursor to the logical start of the word. If the insertion cursor is at the logical start of the line, it moves the insertion cursor to the logical start of the logical last word in the previous line if one exists, otherwise the insertion cursor position doesn't change.

If the XmNeditPolicy is XmEDIT_VISUAL and is called without arguments, it moves the insertion cursor to the first non-white space character after the first white space character to the left or after the beginning of the line. If the insertion cursor is already at the beginning of the word, it moves the insertion cursor to the beginning of the previous word. If the insertion cursor is already at the beginning of the line, it moves to the starting of the last word in the previous 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 it is called with an extend argument, this may 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 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 may 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 may 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 may 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 may 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.

delete-left-word()

If the XmNeditPolicy is XmEDIT_VISUAL, it is equivalent to delete-prev-word(). If the XmNeditPolicy is XmEDIT_LOGICAL, then in normal mode, if there is a non-null selection, it deletes the selection; otherwise, it deletes the characters left of the insertion cursor to the next space, punctuation character, tab, or beginning-of-line character. In add mode, if there is a non-null selection, the cursor is not disjointed from the selection; otherwise it deletes the characters left of the insertion cursor the right space, tab, or beginning-of-line character. In add mode, if there is a non-null selection, the cursor is not disjointed from the selection, the XmNpendingDelete is set to True, and the selection is deleted; otherwise, it deletes the character left of the insertion cursor, the right space, tab, or beginning of new-line character. This may impact the selection.

delete-right-word()

If the XmNeditPolicy is XmEDIT_VISUAL, it is equivalent to delete-right-word(). If the XmNeditPolicy is XmEDIT_LOGICAL, then in normal mode, if there is a non-null selection, it deletes the selection; otherwise, it deletes the characters right of the insertion cursor to the next space, punctuation character, tab, or end-of-line character. In add mode, if there is a non-null selection, the cursor is not disjointed from the selection, XmNpendingDelete is set to True, and deletes the selection; otherwise, it deletes the characters right of the insertion cursor to the next space, tab, or end-of-line character. This may impact the selection.

kill-left-character()

If the XmNeditPolicy is XmEDIT_LOGICAL, it is equivalent to kill-prev-char. If the XmNeditPolicy is XmEDIT_VISUAL, then in normal mode, if there is a non-null selection, it deletes the selection; otherwise, it kills the character left of the insertion cursor and stores the character in the cut buffer. In add mode, if there is a non-null selection, the cursor is not disjointed from the selection, XmNpendingDelete is set to True, and deletes the selection; otherwise, it deletes the character left of the insertion cursor. This may impact the selection.

The kill-left-character() action produces calls to the XmNmodifyVerifyCallback procedures with the reason value XmCR_MODIFYING_TEXT_VALUE, and produces the XmNvalueChangedCallback procedures with the reason value XmCR_VALUE_CHANGED.

kill-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 and stores it in the cut buffer. In add mode, if there is a non-null selection, the cursor is not disjointed from the selection, the XmNpendingDelete is set to True and deletes the selection; otherwise, it deletes the character right of the insertion cursor. This may impact the selection.

The kill-right-character() action produces calls to the XmNmodifyVerify-Callback procedures with reason value XmCR_MODIFYING_TEXT_VALUE, and produces calls to the XmNvalue-ChangedCallback procedures with reason value XmCR_VALUE_CHANGED.

kill-left-word()

If the XmNeditPolicy is XmEDIT_VISUAL, it is equivalent to delete-prev-word(). If the XmNeditPolicy is XmEDIT_LOGICAL, then in normal mode, if there is a non-null selection, it deletes the selection; otherwise, it deletes the characters left of the insertion cursor to the next space, punctuation character, tab, or beginning-of-line character. In add mode, if there is a non-null selection, the cursor is not disjointed from the selection; otherwise it deletes the characters left of the insertion cursor the right space, tab, or beginning-of-line character and stores it in the cut buffer. In add mode, if there is a non-null selection, the cursor is not disjointed from the selection, XmNpendingDelete is set to True and deletes the selection; otherwise it deletes the characters left of the insertion cursor the right space, tab, or beginning of new-line character. This may impact the selection.

kill-right-word()

If the XmNeditPolicy is XmEDIT_VISUAL, it is equivalent to delete-right-word(). If the XmNeditPolicy is XmEDIT_LOGICAL, then in normal mode, if there is a non-null selection, it deletes the selection; otherwise, it deletes the characters right of the insertion cursor to the next space, tab, or end-of-line character. In add mode, if there is a non-null selection, the cursor is not disjointed from the selection, XmNpendingDelete is set to True, and deletes the selection; otherwise, it deletes the characters right of the insertion cursor to the next space, punctuation character, tab, or end-of-line character and stores in the cut buffer. This may impact the selection.

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:

prev-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 may 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 exits; 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 may produce calls to the XmNgainPrimaryCallback procedures. See the callback description in the Motif Programmer's Reference for more information.