3 * Provides a state machine implementation of the various button policies
5 * Author: Allan Rae <rae@lyx.org>
7 * ======================================================
9 * LyX, The Document Processor
11 * Copyright 1995 Matthias Ettrich
12 * Copyright 1995-2000 The LyX Team.
14 * This file Copyright 2000
16 * ======================================================
19 #ifndef BUTTONPOLICIES_H
20 #define BUTTONPOLICIES_H
24 #include <boost/utility.hpp>
26 #include "support/LOstream.h"
28 /** An abstract base class for button policies.
29 A state machine implementation of the various button policies used by the
30 dialogs. Only the policy is implemented here. Separate ButtonController
31 classes are needed for each GUI implementation.
33 Policy | ReadOnly | Apply Button | Repeated Apply
34 ========================================================================
36 OkCancelReadOnly | Y | N | -
37 OkApplyCancel | N | Y | Y
38 OkApplyCancelReadOnly | Y | Y | Y
39 NoRepeatedApply | N | Y | N
40 NoRepeatedApplyReadOnly | Y | Y | N
41 Preferences | N | Y | No (Ok-Close)
42 Ignorant | N/A | N/A | N/A
43 ========================================================================
46 The name of the policy
48 Does the policy treat read-only docs differently to read-write docs?
49 This usually means that when an SMI_READ_ONLY input arrives then
50 all the buttons are disabled except Cancel/Close. The state
51 machine tracks the inputs (valid/invalid) and has states for all
52 combinations. When an SMI_READ_WRITE input arrives the appropriate
53 machine state is entered (just as if the document had always been
55 NOTE: If a dialog doesn't care about the read-only status of a document
56 (and uses an appropriate policy) it can never get into a read-only state
57 so isReadOnly() can only ever return false even though the document may
60 Simply means that it is alright to use the Apply button multiple times
61 without requiring a change of the dialog contents. If no repeating is
62 allowed the Ok+Apply buttons are deactivated. The Preferences dialog
63 has its own special version of repeated apply handling because its Ok
64 button is actually a Save button -- its always reasonable to Save the
65 preferences if the dialog has changed since the last save.
67 The IgnorantPolicy is a special case that allows anything.
69 class ButtonPolicy : public noncopyable {
72 virtual ~ButtonPolicy() {}
74 /** The various possible state names.
75 Not all state-machines have this many states. However, we need
76 to define them all here so we can share the code.
99 /// The various button types.
102 CLOSE = 0, // Not a real button, but effectively !CANCEL
113 static const Button ALL_BUTTONS =
114 Button(OKAY | APPLY | CANCEL | UNDO_ALL);
116 /** State machine inputs.
117 All the policies so far have both CANCEL and HIDE always going to
118 INITIAL. This won't necessarily be true for all [future] policies
119 though so I'll leave those two as distinct inputs rather than merge
120 them. For example, a dialog that doesn't update it's input fields
121 when reshown after being hidden needs a policy where CANCEL and
122 HIDE are treated differently.
144 SMI_TOTAL // not a real input
147 /// Trigger a transition with this input.
148 virtual void input(SMInput) = 0;
149 /// Activation status of a button
150 virtual bool buttonStatus(Button) const = 0;
151 /// Are we in a read-only state?
152 virtual bool isReadOnly() const = 0;
154 /// Transition map of the state machine.
155 typedef std::vector<State> StateArray;
157 typedef std::vector<StateArray> StateMachine;
158 /// The state outputs are the status of the buttons.
159 typedef std::vector<int> StateOutputs;
164 std::ostream & operator<<(std::ostream & os, ButtonPolicy::State st)
172 std::ostream & operator<<(std::ostream & os, ButtonPolicy::SMInput smi)
179 //--------------------- Actual Policy Classes -----------------------------
181 /** Ok and Cancel buttons for dialogs with read-only operation.
182 Note: This scheme supports the relabelling of Cancel to Close and
184 This is based on the value of the bool state of the Button::CANCEL.
185 true == Cancel, false == Close
187 class OkCancelPolicy : public ButtonPolicy {
192 //virtual ~OkCancelPolicy() {}
194 /// Trigger a transition with this input.
195 virtual void input(SMInput);
196 /** Activation status of a button.
197 We assume that we haven't gotten into an undefined state.
198 This is reasonable since we can only reach states defined
199 in the state machine and they should all have been defined in
200 the outputs_ variable. Perhaps we can do something at compile
201 time to check that all the states have corresponding outputs.
203 virtual bool buttonStatus(Button button) const {
204 return button & outputs_[state_];
206 /// Are we in a read-only state?
207 virtual bool isReadOnly() const {
213 /// Which buttons are active for a given state.
214 StateOutputs outputs_;
216 StateMachine state_machine_;
220 /** Ok and Cancel buttons for dialogs where read-only operation is blocked.
221 The state machine design for this policy allows changes to occur within
222 the dialog while a file is read-only -- the okay button is disabled until
223 a read-write input is given. When the file is made read-write the dialog
224 will then be in the correct state (as if the file had always been read-write).
225 Note: This scheme supports the relabelling of Cancel to Close and vice versa.
226 This is based on the value of the bool state of the Button::CANCEL.
227 true == Cancel, false == Close
229 class OkCancelReadOnlyPolicy : public ButtonPolicy {
232 OkCancelReadOnlyPolicy();
234 //virtual ~OkCancelReadOnlyPolicy() {}
236 /// Trigger a transition with this input.
237 virtual void input(SMInput);
238 /// Activation status of a button.
239 virtual bool buttonStatus(Button button) const {
240 return button & outputs_[state_];
242 /// Are we in a read-only state?
243 virtual bool isReadOnly() const {
244 return RO_INITIAL == state_
245 || RO_VALID == state_
246 || RO_INVALID == state_
247 || RO_APPLIED == state_;
252 /// Which buttons are active for a given state.
253 StateOutputs outputs_;
255 StateMachine state_machine_;
259 /** Ok, Apply and Cancel buttons for dialogs where read-only operation is blocked.
260 Repeated Apply are not allowed. Likewise, Ok cannot follow Apply without
261 some valid input. That is, the dialog contents must change between each Apply
263 The state machine design for this policy allows changes to occur within
264 the dialog while a file is read-only -- the Ok+Apply buttons are disabled
265 until a read-write input is given. When the file is made read-write the
266 dialog will then be in the correct state (as if the file had always been
268 Note: This scheme supports the relabelling of Cancel to Close and vice versa.
269 This is based on the value of the bool state of the Button::CANCEL.
270 true == Cancel, false == Close
272 class NoRepeatedApplyReadOnlyPolicy : public ButtonPolicy
276 NoRepeatedApplyReadOnlyPolicy();
278 //virtual ~NoRepeatedApplyReadOnlyPolicy() {}
280 /// Trigger a transition with this input.
281 virtual void input(SMInput);
282 /// Activation status of a button.
283 virtual bool buttonStatus(Button button) const {
284 return button & outputs_[state_];
286 /// Are we in a read-only state?
287 virtual bool isReadOnly() const {
288 return RO_INITIAL == state_
289 || RO_VALID == state_
290 || RO_INVALID == state_
291 || RO_APPLIED == state_;
296 /// Which buttons are active for a given state.
297 StateOutputs outputs_;
299 StateMachine state_machine_;
303 /** Ok, Apply and Cancel buttons for dialogs where read-only operation is blocked.
304 Repeated Apply is allowed. Likewise, Ok can follow Apply.
305 The state machine design for this policy allows changes to occur within
306 the dialog while a file is read-only -- the Ok+Apply buttons are disabled
307 until a read-write input is given. When the file is made read-write the
308 dialog will then be in the correct state (as if the file had always been
310 Note: This scheme supports the relabelling of Cancel to Close and vice versa.
311 This is based on the value of the bool state of the Button::CANCEL.
312 true == Cancel, false == Close
314 class OkApplyCancelReadOnlyPolicy : public ButtonPolicy {
317 OkApplyCancelReadOnlyPolicy();
319 //virtual ~OkApplyCancelReadOnlyPolicy() {}
321 /// Trigger a transition with this input.
322 virtual void input(SMInput);
323 /// Activation status of a button.
324 virtual bool buttonStatus(Button button) const {
325 return button & outputs_[state_];
327 /// Are we in a read-only state?
328 virtual bool isReadOnly() const {
329 return RO_INITIAL == state_
330 || RO_VALID == state_
331 || RO_INVALID == state_
332 || RO_APPLIED == state_;
337 /// Which buttons are active for a given state.
338 StateOutputs outputs_;
340 StateMachine state_machine_;
344 /** Ok, Apply and Cancel buttons for dialogs where repeated Apply is allowed.
345 Note: This scheme supports the relabelling of Cancel to Close and vice versa.
346 This is based on the value of the bool state of the Button::CANCEL.
347 true == Cancel, false == Close
349 class OkApplyCancelPolicy : public ButtonPolicy {
352 OkApplyCancelPolicy();
354 //virtual ~OkApplyCancelPolicy() {}
356 /// Trigger a transition with this input.
357 virtual void input(SMInput);
358 /// Activation status of a button.
359 virtual bool buttonStatus(Button button) const {
360 return button & outputs_[state_];
362 /// Are we in a read-only state?
363 virtual bool isReadOnly() const {
369 /// Which buttons are active for a given state.
370 StateOutputs outputs_;
372 StateMachine state_machine_;
376 /** Ok, Apply and Cancel buttons for dialogs with no repeated Apply.
377 Note: This scheme supports the relabelling of Cancel to Close and vice versa.
378 This is based on the value of the bool state of the Button::CANCEL.
379 true == Cancel, false == Close
381 class NoRepeatedApplyPolicy : public ButtonPolicy {
384 NoRepeatedApplyPolicy();
386 //virtual ~NoRepeatedApplyPolicy() {}
388 /// Trigger a transition with this input.
389 virtual void input(SMInput);
390 /// Activation status of a button.
391 virtual bool buttonStatus(Button button) const {
392 return button & outputs_[state_];
394 /// Are we in a read-only state?
395 virtual bool isReadOnly() const {
401 /// Which buttons are active for a given state.
402 StateOutputs outputs_;
404 StateMachine state_machine_;
408 /** Defines the policy used by the Preferences dialog.
409 Four buttons: Ok (Save), Apply, Cancel/Close, Restore.
410 Note: This scheme supports the relabelling of Cancel to Close and vice versa.
411 This is based on the value of the bool state of the Button::CANCEL.
412 true == Cancel, false == Close
414 class PreferencesPolicy : public ButtonPolicy {
419 //virtual ~PreferencesPolicy() {}
421 /// Trigger a transition with this input.
422 virtual void input(SMInput);
423 /// Activation status of a button.
424 virtual bool buttonStatus(Button button) const {
425 return button & outputs_[state_];
427 /// Are we in a read-only state?
428 virtual bool isReadOnly() const {
434 /// Which buttons are active for a given state.
435 StateOutputs outputs_;
437 StateMachine state_machine_;
441 /** Defines the policy used by dialogs that are forced to support a button
442 controller when they either don't have a use for one or are not ready to
443 use one. This may be useful when testing a new button policy but wishing
444 to minimise problems to users by supplying an anything-goes policy via a
445 preprocessor directive.
447 class IgnorantPolicy : public ButtonPolicy {
449 //virtual ~IgnorantPolicy() {}
451 /// Trigger a transition with this input.
452 virtual void input(SMInput) {}
453 /// Activation status of a button.
454 virtual bool buttonStatus(Button) const {
457 /// Are we in a read-only state?
458 virtual bool isReadOnly() const {