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_;
219 /** Ok and Cancel buttons for dialogs where read-only operation is blocked.
220 The state machine design for this policy allows changes to occur within
221 the dialog while a file is read-only -- the okay button is disabled until
222 a read-write input is given. When the file is made read-write the dialog
223 will then be in the correct state (as if the file had always been
225 Note: This scheme supports the relabelling of Cancel to Close
227 This is based on the value of the bool state of the Button::CANCEL.
228 true == Cancel, false == Close
230 class OkCancelReadOnlyPolicy : public ButtonPolicy {
233 OkCancelReadOnlyPolicy();
235 //virtual ~OkCancelReadOnlyPolicy() {}
237 /// Trigger a transition with this input.
238 virtual void input(SMInput);
239 /// Activation status of a button.
240 virtual bool buttonStatus(Button button) const {
241 return button & outputs_[state_];
243 /// Are we in a read-only state?
244 virtual bool isReadOnly() const {
245 return RO_INITIAL == state_
246 || RO_VALID == state_
247 || RO_INVALID == state_
248 || RO_APPLIED == state_;
253 /// Which buttons are active for a given state.
254 StateOutputs outputs_;
256 StateMachine state_machine_;
260 /** Ok, Apply and Cancel buttons for dialogs where read-only operation
262 Repeated Apply are not allowed. Likewise, Ok cannot follow Apply without
263 some valid input. That is, the dialog contents must change between
264 each Apply or Apply and Ok.
265 The state machine design for this policy allows changes to occur within
266 the dialog while a file is read-only -- the Ok+Apply buttons are disabled
267 until a read-write input is given. When the file is made read-write the
268 dialog will then be in the correct state (as if the file had always been
270 Note: This scheme supports the relabelling of Cancel to Close
272 This is based on the value of the bool state of the Button::CANCEL.
273 true == Cancel, false == Close
275 class NoRepeatedApplyReadOnlyPolicy : public ButtonPolicy
279 NoRepeatedApplyReadOnlyPolicy();
281 //virtual ~NoRepeatedApplyReadOnlyPolicy() {}
283 /// Trigger a transition with this input.
284 virtual void input(SMInput);
285 /// Activation status of a button.
286 virtual bool buttonStatus(Button button) const {
287 return button & outputs_[state_];
289 /// Are we in a read-only state?
290 virtual bool isReadOnly() const {
291 return RO_INITIAL == state_
292 || RO_VALID == state_
293 || RO_INVALID == state_
294 || RO_APPLIED == state_;
299 /// Which buttons are active for a given state.
300 StateOutputs outputs_;
302 StateMachine state_machine_;
306 /** Ok, Apply and Cancel buttons for dialogs where read-only
307 operation is blocked.
308 Repeated Apply is allowed. Likewise, Ok can follow Apply.
309 The state machine design for this policy allows changes to occur within
310 the dialog while a file is read-only -- the Ok+Apply buttons are disabled
311 until a read-write input is given. When the file is made read-write the
312 dialog will then be in the correct state (as if the file had always been
314 Note: This scheme supports the relabelling of Cancel to Close
316 This is based on the value of the bool state of the Button::CANCEL.
317 true == Cancel, false == Close
319 class OkApplyCancelReadOnlyPolicy : public ButtonPolicy {
322 OkApplyCancelReadOnlyPolicy();
324 //virtual ~OkApplyCancelReadOnlyPolicy() {}
326 /// Trigger a transition with this input.
327 virtual void input(SMInput);
328 /// Activation status of a button.
329 virtual bool buttonStatus(Button button) const {
330 return button & outputs_[state_];
332 /// Are we in a read-only state?
333 virtual bool isReadOnly() const {
334 return RO_INITIAL == state_
335 || RO_VALID == state_
336 || RO_INVALID == state_
337 || RO_APPLIED == state_;
342 /// Which buttons are active for a given state.
343 StateOutputs outputs_;
345 StateMachine state_machine_;
349 /** Ok, Apply and Cancel buttons for dialogs where repeated Apply is allowed.
350 Note: This scheme supports the relabelling of Cancel to Close
352 This is based on the value of the bool state of the Button::CANCEL.
353 true == Cancel, false == Close
355 class OkApplyCancelPolicy : public ButtonPolicy {
358 OkApplyCancelPolicy();
360 //virtual ~OkApplyCancelPolicy() {}
362 /// Trigger a transition with this input.
363 virtual void input(SMInput);
364 /// Activation status of a button.
365 virtual bool buttonStatus(Button button) const {
366 return button & outputs_[state_];
368 /// Are we in a read-only state?
369 virtual bool isReadOnly() const {
375 /// Which buttons are active for a given state.
376 StateOutputs outputs_;
378 StateMachine state_machine_;
382 /** Ok, Apply and Cancel buttons for dialogs with no repeated Apply.
383 Note: This scheme supports the relabelling of Cancel to Close
385 This is based on the value of the bool state of the Button::CANCEL.
386 true == Cancel, false == Close
388 class NoRepeatedApplyPolicy : public ButtonPolicy {
391 NoRepeatedApplyPolicy();
393 //virtual ~NoRepeatedApplyPolicy() {}
395 /// Trigger a transition with this input.
396 virtual void input(SMInput);
397 /// Activation status of a button.
398 virtual bool buttonStatus(Button button) const {
399 return button & outputs_[state_];
401 /// Are we in a read-only state?
402 virtual bool isReadOnly() const {
408 /// Which buttons are active for a given state.
409 StateOutputs outputs_;
411 StateMachine state_machine_;
415 /** Defines the policy used by the Preferences dialog.
416 Four buttons: Ok (Save), Apply, Cancel/Close, Restore.
417 Note: This scheme supports the relabelling of Cancel to Close
419 This is based on the value of the bool state of the Button::CANCEL.
420 true == Cancel, false == Close
422 class PreferencesPolicy : public ButtonPolicy {
427 //virtual ~PreferencesPolicy() {}
429 /// Trigger a transition with this input.
430 virtual void input(SMInput);
431 /// Activation status of a button.
432 virtual bool buttonStatus(Button button) const {
433 return button & outputs_[state_];
435 /// Are we in a read-only state?
436 virtual bool isReadOnly() const {
442 /// Which buttons are active for a given state.
443 StateOutputs outputs_;
445 StateMachine state_machine_;
449 /** Defines the policy used by dialogs that are forced to support a button
450 controller when they either don't have a use for one or are not ready to
451 use one. This may be useful when testing a new button policy but wishing
452 to minimise problems to users by supplying an anything-goes policy via a
453 preprocessor directive.
455 class IgnorantPolicy : public ButtonPolicy {
457 //virtual ~IgnorantPolicy() {}
459 /// Trigger a transition with this input.
460 virtual void input(SMInput) {}
461 /// Activation status of a button.
462 virtual bool buttonStatus(Button) const {
465 /// Are we in a read-only state?
466 virtual bool isReadOnly() const {