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Text File | 1994-09-20 | 19.6 KB | 529 lines

bind(n) Tk Commands _________________________________________________________________ NAME bind - Arrange for X events to invoke Tcl commands SYNOPSIS bind _w_i_n_d_o_w_S_p_e_c bind _w_i_n_d_o_w_S_p_e_c _s_e_q_u_e_n_c_e bind _w_i_n_d_o_w_S_p_e_c _s_e_q_u_e_n_c_e _c_o_m_m_a_n_d bind _w_i_n_d_o_w_S_p_e_c _s_e_q_u_e_n_c_e +_c_o_m_m_a_n_d _________________________________________________________________ DESCRIPTION If all three arguments are specified, bind will arrange for _c_o_m_m_a_n_d (a Tcl command) to be executed whenever the sequence of events given by _s_e_q_u_e_n_c_e occurs in the window(s) identi- | fied by _w_i_n_d_o_w_S_p_e_c. If _c_o_m_m_a_n_d is prefixed with a ``+'', then it is appended to any existing binding for _s_e_q_u_e_n_c_e; otherwise _c_o_m_m_a_n_d replaces the existing binding, if any. If _c_o_m_m_a_n_d is an empty string then the current binding for _s_e_q_u_e_n_c_e is destroyed, leaving _s_e_q_u_e_n_c_e unbound. In all of the cases where a _c_o_m_m_a_n_d argument is provided, bind returns an empty string. If _s_e_q_u_e_n_c_e is specified without a _c_o_m_m_a_n_d, then the command currently bound to _s_e_q_u_e_n_c_e is returned, or an empty string if there is no binding for _s_e_q_u_e_n_c_e. If neither _s_e_q_u_e_n_c_e nor _c_o_m_m_a_n_d is specified, then the return value is a list whose elements are all the sequences for which there exist | bindings for _w_i_n_d_o_w_S_p_e_c. | The _w_i_n_d_o_w_S_p_e_c argument selects which window(s) the binding | applies to. It may have one of three forms. If _w_i_n_d_o_w_S_p_e_c | is the path name for a window, then the binding applies to | that particular window. If _w_i_n_d_o_w_S_p_e_c is the name of a | class of widgets, then the binding applies to all widgets in | that class. Lastly, _w_i_n_d_o_w_S_p_e_c may have the value all, in | which case the binding applies to all windows in the appli- | cation. The _s_e_q_u_e_n_c_e argument specifies a sequence of one or more event patterns, with optional white space between the pat- terns. Each event pattern may take either of two forms. In the simplest case it is a single printing ASCII character, such as a or [. The character may not be a space character or the character <. This form of pattern matches a KeyPress event for the particular character. The second form of pat- tern is longer but more general. It has the following syn- tax: <_m_o_d_i_f_i_e_r-_m_o_d_i_f_i_e_r-_t_y_p_e-_d_e_t_a_i_l> Tk 1 bind(n) Tk Commands The entire event pattern is surrounded by angle brackets. Inside the angle brackets are zero or more modifiers, an event type, and an extra piece of information (_d_e_t_a_i_l) iden- tifying a particular button or keysym. Any of the fields may be omitted, as long as at least one of _t_y_p_e and _d_e_t_a_i_l is present. The fields must be separated by white space or dashes. Modifiers may consist of any of the values in the following list: Control Any Shift Double Lock Triple Button1, B1 Mod1, M1, Meta, M | Button2, B2 Mod2, M2, Alt | Button3, B3 Mod3, M3 Button4, B4 Mod4, M4 Button5, B5 Mod5, M5 Where more than one value is listed, separated by commas, the values are equivalent. All of the modifiers except Any, Double, and Triple have the obvious X meanings. For example, Button1 requires that button 1 be depressed when the event occurs. Under normal conditions the button and modifier state at the time of the event must match exactly those specified in the bind command. If no modifiers are specified, then events will match only if no modifiers are present. If the Any modifier is specified, then additional modifiers may be present besides those specified explicitly. For example, if button 1 is pressed while the shift and con- trol keys are down, the specifier <Any-Control-Button-1> will match the event, but the specifier <Control-Button-1> will not. The Double and Triple modifiers are a convenience for speci- fying double mouse clicks and other repeated events. They cause a particular event pattern to be repeated 2 or 3 times, and also place a time and space requirement on the sequence: for a sequence of events to match a Double or Triple pattern, all of the events must occur close together in time and without substantial mouse motion in between. For example, <Double-Button-1> is equivalent to <Button- 1><Button-1> with the extra time and space requirement. The _t_y_p_e field may be any of the standard X event types, with a few extra abbreviations. Below is a list of all the valid types; where two name appear together, they are synonyms. ButtonPress, Button Expose Leave ButtonRelease FocusIn Map Circulate FocusOut Property Tk 2 bind(n) Tk Commands CirculateRequest Gravity Reparent Colormap Keymap ResizeRequest Configure KeyPress, Key Unmap ConfigureRequest KeyRelease Visibility | Destroy MapRequest Enter Motion The last part of a long event specification is _d_e_t_a_i_l. In the case of a ButtonPress or ButtonRelease event, it is the number of a button (1-5). If a button number is given, then only an event on that particular button will match; if no button number is given, then an event on any button will match. Note: giving a specific button number is different than specifying a button modifier; in the first case, it refers to a button being pressed or released, while in the second it refers to some other button that is already depressed when the matching event occurs. If a button number is given then _t_y_p_e may be omitted: if will default to ButtonPress. For example, the specifier <1> is equivalent to <ButtonPress-1>. If the event type is KeyPress or KeyRelease, then _d_e_t_a_i_l may be specified in the form of an X keysym. Keysyms are tex- tual specifications for particular keys on the keyboard; they include all the alphanumeric ASCII characters (e.g. ``a'' is the keysym for the ASCII character ``a''), plus descriptions for non-alphanumeric characters (``comma'' is the keysym for the comma character), plus descriptions for all the non-ASCII keys on the keyboard (``Shift_L'' is the keysm for the left shift key, and ``F1'' is the keysym for the F1 function key, if it exists). The complete list of keysyms is not presented here; it should be available in other X documentation. If necessary, you can use the %K notation described below to print out the keysym name for an arbitrary key. If a keysym _d_e_t_a_i_l is given, then the _t_y_p_e field may be omitted; it will default to KeyPress. For example, <Control-comma> is equivalent to <Control- KeyPress-comma>. If a keysym _d_e_t_a_i_l is specified then the Shift modifier need not be specified and will be ignored if specified: each keysym already implies a particular state for the shift key. The _c_o_m_m_a_n_d argument to bind is a Tcl command string, which will be executed whenever the given event sequence occurs. _C_o_m_m_a_n_d will be executed in the same interpreter that the bind command was executed in. If _c_o_m_m_a_n_d contains any % characters, then the command string will not be executed directly. Instead, a new command string will be generated by replacing each %, and the character following it, with information from the current event. The replacement depends on the character following the %, as defined in the list below. Unless otherwise indicated, the replacement string | Tk 3 bind(n) Tk Commands is the decimal value of the given field from the current | event. Some of the substitutions are only valid for certain types of events; if they are used for other types of events the value substituted is undefined. %% Replaced with a single percent. %# The number of the last client request processed by the server (the _s_e_r_i_a_l field from the event). Valid for all event types. %a The _a_b_o_v_e field from the event. Valid only for Confi- gureNotify events. %b The number of the button that was pressed or released. Valid only for ButtonPress and ButtonRelease events. %c The _c_o_u_n_t field from the event. Valid only for Expose, GraphicsExpose, and MappingNotify events. %d The _d_e_t_a_i_l field from the event. The %d is replaced by a string identifying the detail. For EnterNotify, LeaveNotify, FocusIn, and FocusOut events, the string will be one of the following: NotifyAncestor NotifyNonlinearVirtual NotifyDetailNone NotifyPointer NotifyInferior NotifyPointerRoot NotifyNonlinear NotifyVirtual For ConfigureRequest events, the substituted string will be one of the following: Above Opposite Below TopIf BottomIf For events other than these, the substituted string is undefined. %f The _f_o_c_u_s field from the event (0 or 1). Valid only for EnterNotify and LeaveNotify events. %h The _h_e_i_g_h_t field from the event. Valid only for Con- figure, ConfigureNotify, Expose, GraphicsExpose, and ResizeRequest events. %k The _k_e_y_c_o_d_e field from the event. Valid only for KeyPress and KeyRelease events. %m The _m_o_d_e field from the event. The substituted string is one of NotifyNormal, NotifyGrab, NotifyUngrab, or NotifyWhileGrabbed. Valid only for EnterWindow, Tk 4 bind(n) Tk Commands FocusIn, FocusOut, and LeaveWindow events. %o The _o_v_e_r_r_i_d_e__r_e_d_i_r_e_c_t field from the event. Valid only for CreateNotify, MapNotify, ReparentNotify, and Confi- gureNotify events. %p The _p_l_a_c_e field from the event, substituted as one of the strings PlaceOnTop or PlaceOnBottom. Valid only for CirculateNotify and CirculateRequest events. %s The _s_t_a_t_e field from the event. For ButtonPress, But- tonRelease, EnterNotify, KeyPress, KeyRelease, LeaveNo- tify, and MotionNotify events, a decimal string is sub- | stituted. For VisibilityNotify, one of the strings VisibilityUnobscured, VisibilityPartiallyObscured, and VisibilityFullyObscured is substituted. %t The _t_i_m_e field from the event. Valid only for events that contain a _t_i_m_e field. %v The _v_a_l_u_e__m_a_s_k field from the event. Valid only for ConfigureRequest events. %w The _w_i_d_t_h field from the event. Valid only for Config- ure, ConfigureRequest, Expose, GraphicsExpose, and ResizeRequest events. %x The _x field from the event. Valid only for events con- taining an _x field. %y The _y field from the event. Valid only for events con- taining a _y field. %A Substitutes the ASCII character corresponding to the event, or the empty string if the event doesn't correspond to an ASCII character (e.g. the shift key was pressed). XLookupString does all the work of translating from the event to an ASCII character. Valid only for KeyPress and KeyRelease events. %B The _b_o_r_d_e_r__w_i_d_t_h field from the event. Valid only for ConfigureNotify and CreateWindow events. %D The _d_i_s_p_l_a_y field from the event. Valid for all event types. %E The _s_e_n_d__e_v_e_n_t field from the event. Valid for all event types. %K The keysym corresponding to the event, substituted as a textual string. Valid only for KeyPress and KeyRelease events. Tk 5 bind(n) Tk Commands %N The keysym corresponding to the event, substituted as a | decimal number. Valid only for KeyPress and KeyRelease events. %R The _r_o_o_t window identifier from the event. Valid only for events containing a _r_o_o_t field. %S The _s_u_b_w_i_n_d_o_w window identifier from the event. Valid only for events containing a _s_u_b_w_i_n_d_o_w field. %T The _t_y_p_e field from the event. Valid for all event types. %W The path name of the window to which the event was reported (the _w_i_n_d_o_w field from the event). Valid for all event types. %X The _x__r_o_o_t field from the event. If a virtual-root | window manager is being used then the substituted value | is the corresponding x-coordinate in the virtual root. Valid only for ButtonPress, ButtonRelease, KeyPress, KeyRelease, and MotionNotify events. %Y The _y__r_o_o_t field from the event. If a virtual-root | window manager is being used then the substituted value | is the corresponding y-coordinate in the virtual root. Valid only for ButtonPress, ButtonRelease, KeyPress, KeyRelease, and MotionNotify events. If the replacement string for a %-replacement contains char- | acters that are interpreted specially by the Tcl parser | (such as backslashes or square brackets or spaces) addi- | tional backslashes are added during replacement so that the | result after parsing is the original replacement string. | For example, if _c_o_m_m_a_n_d is | insert %A | and the character typed is an open square bracket, then the | command actually executed will be | insert \[ | This will cause the insert to receive the original replace- | ment string (open square bracket) as its first argument. If | the extra backslash hadn't been added, Tcl would not have | been able to parse the command correctly. At most one binding will trigger for any given X event. If several bindings match the recent events, the most specific binding is chosen and its command will be executed. The following tests are applied, in order, to determine which of several matching sequences is more specific: (a) a binding | Tk 6 bind(n) Tk Commands whose _w_i_n_d_o_w_S_p_e_c names a particular window is more specific | than a binding for a class, which is more specific than a | binding whose _w_i_n_d_o_w_S_p_e_c is all; (b) a longer sequence (in terms of number of events matched) is more specific than a shorter sequence; (c) an event pattern that specifies a specific button or key is more specific than one that doesn't; (e) an event pattern that requires a particular modifier is more specific than one that doesn't require the modifier; (e) an event pattern specifying the Any modifier is less specific than one that doesn't. If the matching sequences contain more than one event, then tests (c)-(e) are applied in order from the most recent event to the least recent event in the sequences. If these tests fail to determine a winner, then the most recently registered sequence is the winner. If an X event does not match any of the existing bindings, then the event is ignored (an unbound event is not con- sidered to be an error). When a _s_e_q_u_e_n_c_e specified in a bind command contains more than one event pattern, then its command is executed when- ever the recent events (leading up to and including the current event) match the given sequence. This means, for example, that if button 1 is clicked repeatedly the sequence <Double-ButtonPress-1> will match each button press but the first. If extraneous events that would prevent a match | occur in the middle of an event sequence then the extraneous | events are ignored unless they are KeyPress or ButtonPress | events. For example, <Double-ButtonPress-1> will match a | sequence of presses of button 1, even though there will be | ButtonRelease events (and possibly MotionNotify events) | between the ButtonPress events. Furthermore, a KeyPress | event may be preceded by any number of other KeyPress events | for modifier keys without the modifier keys preventing a | match. For example, the event sequence aB will match a | press of the a key, a release of the a key, a press of the | Shift key, and a press of the b key: the press of Shift is | ignored because it is a modifier key. Finally, if several MotionNotify events occur in a row, only the last one is used for purposes of matching binding sequences. If an error occurs in executing the command for a binding then the tkerror mechanism is used to report the error. The | command will be executed at global level (outside the con- | text of any Tcl procedure). SEE ALSO tkerror Tk 7 bind(n) Tk Commands KEYWORDS form, manual Tk 8