src/common/containr.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/containr.cpp
   3 // Purpose:     implementation of wxControlContainer
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     06.08.01
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2001 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // License:     wxWindows license
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #ifdef __GNUG__
  21     #pragma implementation "containr.h"
  22 #endif
  23
  24 // For compilers that support precompilation, includes "wx.h".
  25 #include "wx/wxprec.h"
  26
  27 #ifdef __BORLANDC__
  28     #pragma hdrstop
  29 #endif
  30
  31 #ifndef WX_PRECOMP
  32     #include "wx/log.h"
  33     #include "wx/event.h"
  34     #include "wx/window.h"
  35 #endif //WX_PRECOMP
  36
  37 #include "wx/containr.h"
  38
  39 // ============================================================================
  40 // implementation
  41 // ============================================================================
  42
  43 wxControlContainer::wxControlContainer(wxWindow *winParent)
  44 {
  45     m_winParent = winParent;
  46
  47     m_winLastFocused =
  48     m_winDefault = NULL;
  49 }
  50
  51 void wxControlContainer::SetLastFocus(wxWindow *win)
  52 {
  53     // if we're setting the focus
  54     if ( win )
  55     {
  56         // find the last _immediate_ child which got focus but be prepared to
  57         // handle the case when win == m_winParent as well
  58         wxWindow *winParent = win;
  59         while ( winParent != m_winParent )
  60         {
  61             win = winParent;
  62             winParent = win->GetParent();
  63
  64             // Yes, this can happen, though in a totally pathological case.
  65             // like when detaching a menubar from a frame with a child which
  66             // has pushed itself as an event handler for the menubar.  (wxGtk)
  67
  68             wxASSERT_MSG( winParent, _T("Setting last-focus for a window that is not our child?") );
  69         }
  70     }
  71
  72     m_winLastFocused = win;
  73 }
  74
  75 // ----------------------------------------------------------------------------
  76 // Keyboard handling - this is the place where the TAB traversal logic is
  77 // implemented. As this code is common to all ports, this ensures consistent
  78 // behaviour even if we don't specify how exactly the wxNavigationKeyEvent are
  79 // generated and this is done in platform specific code which also ensures that
  80 // we can follow the given platform standards.
  81 // ----------------------------------------------------------------------------
  82
  83 void wxControlContainer::HandleOnNavigationKey( wxNavigationKeyEvent& event )
  84 {
  85     wxWindow *parent = m_winParent->GetParent();
  86
  87     // the event is propagated downwards if the event emitter was our parent
  88     bool goingDown = event.GetEventObject() == parent;
  89
  90     const wxWindowList& children = m_winParent->GetChildren();
  91
  92     // there is not much to do if we don't have children and we're not
  93     // interested in "notebook page change" events here
  94     if ( !children.GetCount() || event.IsWindowChange() )
  95     {
  96         // let the parent process it unless it already comes from our parent
  97         // of we don't have any
  98         if ( goingDown ||
  99              !parent || !parent->GetEventHandler()->ProcessEvent(event) )
 100         {
 101             event.Skip();
 102         }
 103
 104         return;
 105     }
 106
 107     // where are we going?
 108     bool forward = event.GetDirection();
 109
 110     // the node of the children list from which we should start looking for the
 111     // next acceptable child
 112     wxWindowList::Node *node, *start_node;
 113
 114     // we should start from the first/last control and not from the one which
 115     // had focus the last time if we're propagating the event downwards because
 116     // for our parent we look like a single control
 117     if ( goingDown )
 118     {
 119         // just to be sure it's not used (normally this is not necessary, but
 120         // doesn't hurt neither)
 121         m_winLastFocused = (wxWindow *)NULL;
 122
 123         // start from first or last depending on where we're going
 124         node = forward ? children.GetFirst() : children.GetLast();
 125
 126         // we want to cycle over all nodes
 127         start_node = (wxWindowList::Node *)NULL;
 128     }
 129     else
 130     {
 131         // try to find the child which has the focus currently
 132
 133         // the event emitter might have done this for us
 134         wxWindow *winFocus = event.GetCurrentFocus();
 135
 136         // but if not, we might know where the focus was ourselves
 137         if (!winFocus)
 138             winFocus = m_winLastFocused;
 139
 140         // if still no luck, do it the hard way
 141         if (!winFocus)
 142             winFocus = wxWindow::FindFocus();
 143
 144         if ( winFocus )
 145         {
 146             // ok, we found the focus - now is it our child?
 147             start_node = children.Find( winFocus );
 148         }
 149         else
 150         {
 151             start_node = (wxWindowList::Node *)NULL;
 152         }
 153
 154         if ( !start_node && m_winLastFocused )
 155         {
 156             // window which has focus isn't our child, fall back to the one
 157             // which had the focus the last time
 158             start_node = children.Find( m_winLastFocused );
 159         }
 160
 161         // if we still didn't find anything, we should start with the first one
 162         if ( !start_node )
 163         {
 164             start_node = children.GetFirst();
 165         }
 166
 167         // and the first child which we can try setting focus to is the next or
 168         // the previous one
 169         node = forward ? start_node->GetNext() : start_node->GetPrevious();
 170     }
 171
 172     // we want to cycle over all elements passing by NULL
 173     while ( node != start_node )
 174     {
 175         // Have we come to the last or first item on the panel?
 176         if ( !node )
 177         {
 178             if ( !goingDown )
 179             {
 180                 // Check if our (may be grand) parent is another panel: if this
 181                 // is the case, they will know what to do with this navigation
 182                 // key and so give them the chance to process it instead of
 183                 // looping inside this panel (normally, the focus will go to
 184                 // the next/previous item after this panel in the parent
 185                 // panel).
 186                 wxWindow *focussed_child_of_parent = m_winParent;
 187                 while ( parent )
 188                 {
 189                     // we don't want to tab into a different dialog or frame
 190                     if ( focussed_child_of_parent->IsTopLevel() )
 191                         break;
 192
 193                     event.SetCurrentFocus( focussed_child_of_parent );
 194                     if ( parent->GetEventHandler()->ProcessEvent( event ) )
 195                         return;
 196
 197                     focussed_child_of_parent = parent;
 198
 199                     parent = parent->GetParent();
 200                 }
 201             }
 202             //else: as the focus came from our parent, we definitely don't want
 203             //      to send it back to it!
 204
 205             // no, we are not inside another panel so process this ourself
 206             node = forward ? children.GetFirst() : children.GetLast();
 207
 208             continue;
 209         }
 210
 211         wxWindow *child = node->GetData();
 212
 213         if ( child->AcceptsFocusFromKeyboard() )
 214         {
 215             // if we're setting the focus to a child panel we should prevent it
 216             // from giving it to the child which had the focus the last time
 217             // and instead give it to the first/last child depending from which
 218             // direction we're coming
 219             event.SetEventObject(m_winParent);
 220             if ( !child->GetEventHandler()->ProcessEvent(event) )
 221             {
 222                 // everything is simple: just give focus to it
 223                 child->SetFocus();
 224
 225                 m_winLastFocused = child;
 226             }
 227             //else: the child manages its focus itself
 228
 229             event.Skip( FALSE );
 230
 231             return;
 232         }
 233
 234         node = forward ? node->GetNext() : node->GetPrevious();
 235     }
 236
 237     // we cycled through all of our children and none of them wanted to accept
 238     // focus
 239     event.Skip();
 240 }
 241
 242 void wxControlContainer::HandleOnWindowDestroy(wxWindowBase *child)
 243 {
 244     if ( child == m_winLastFocused )
 245         m_winLastFocused = NULL;
 246
 247     if ( child == m_winDefault )
 248         m_winDefault = NULL;
 249 }
 250
 251 // ----------------------------------------------------------------------------
 252 // focus handling
 253 // ----------------------------------------------------------------------------
 254
 255 bool wxControlContainer::DoSetFocus()
 256 {
 257     wxLogTrace(_T("focus"), _T("SetFocus on wxPanel 0x%08x."),
 258                m_winParent->GetHandle());
 259
 260     // If the panel gets the focus *by way of getting it set directly*
 261     // we move the focus to the first window that can get it.
 262
 263     // VZ: no, we set the focus to the last window too. I don't understand why
 264     //     should we make this distinction: if an app wants to set focus to
 265     //     some precise control, it may always do it directly, but if we don't
 266     //     use m_winLastFocused here, the focus won't be set correctly after a
 267     //     notebook page change nor after frame activation under MSW (it calls
 268     //     SetFocus too)
 269     //
 270     // RR: yes, when I the tab key to navigate in a panel with some controls and
 271     //     a notebook and the focus jumps to the notebook (typically coming from
 272     //     a button at the top) the notebook should focus the first child in the
 273     //     current notebook page, not the last one which would otherwise get the
 274     //     focus if you used the tab key to navigate from the current notebook
 275     //     page to button at the bottom. See every page in the controls sample.
 276     //
 277     // VZ: ok, but this still doesn't (at least I don't see how it can) take
 278     //     care of first/last child problem: i.e. if Shift-TAB is pressed in a
 279     //     situation like above, the focus should be given to the last child,
 280     //     not the first one (and not to the last focused one neither) - I
 281     //     think my addition to OnNavigationKey() above takes care of it.
 282     //     Keeping #ifdef __WXGTK__ for now, but please try removing it and see
 283     //     what happens.
 284     //
 285     // RR: Removed for now. Let's see what happens..
 286
 287     // if our child already has focus, don't take it away from it
 288     wxWindow *win = wxWindow::FindFocus();
 289     while ( win )
 290     {
 291         if ( win == m_winParent )
 292             return TRUE;
 293
 294         if ( win->IsTopLevel() )
 295         {
 296             // don't look beyond the first top level parent - useless and
 297             // unnecessary
 298             break;
 299         }
 300
 301         win = win->GetParent();
 302     }
 303
 304     return SetFocusToChild();
 305 }
 306
 307 void wxControlContainer::HandleOnFocus(wxFocusEvent& event)
 308 {
 309     wxLogTrace(_T("focus"), _T("OnFocus on wxPanel 0x%08x, name: %s"),
 310                m_winParent->GetHandle(),
 311                m_winParent->GetName().c_str() );
 312
 313     // If we panel got the focus *by way of getting clicked on*
 314     // we move the focus to either the last window that had the
 315     // focus or the first one that can get it.
 316     (void)SetFocusToChild();
 317
 318     event.Skip();
 319 }
 320
 321 bool wxControlContainer::SetFocusToChild()
 322 {
 323     return wxSetFocusToChild(m_winParent, &m_winLastFocused);
 324 }
 325
 326 // ----------------------------------------------------------------------------
 327 // SetFocusToChild(): this function is used by wxPanel but also by wxFrame in
 328 // wxMSW, this is why it is outside of wxControlContainer class
 329 // ----------------------------------------------------------------------------
 330
 331 bool wxSetFocusToChild(wxWindow *win, wxWindow **childLastFocused)
 332 {
 333     wxCHECK_MSG( win, FALSE, _T("wxSetFocusToChild(): invalid window") );
 334
 335     if ( *childLastFocused )
 336     {
 337         // It might happen that the window got reparented or no longer accepts
 338         // the focus.
 339         if ( (*childLastFocused)->GetParent() == win &&
 340              (*childLastFocused)->AcceptsFocusFromKeyboard() )
 341         {
 342             wxLogTrace(_T("focus"),
 343                        _T("SetFocusToChild() => last child (0x%08x)."),
 344                        (*childLastFocused)->GetHandle());
 345
 346             (*childLastFocused)->SetFocus();
 347             return TRUE;
 348         }
 349         else
 350         {
 351             // it doesn't count as such any more
 352             *childLastFocused = (wxWindow *)NULL;
 353         }
 354     }
 355
 356     // set the focus to the first child who wants it
 357     wxWindowList::Node *node = win->GetChildren().GetFirst();
 358     while ( node )
 359     {
 360         wxWindow *child = node->GetData();
 361
 362         if ( child->AcceptsFocusFromKeyboard() && !child->IsTopLevel() )
 363         {
 364             wxLogTrace(_T("focus"),
 365                        _T("SetFocusToChild() => first child (0x%08x)."),
 366                        child->GetHandle());
 367
 368             *childLastFocused = child;  // should be redundant, but it is not
 369             child->SetFocus();
 370             return TRUE;
 371         }
 372
 373         node = node->GetNext();
 374     }
 375
 376     return FALSE;
 377 }