+// ----------------------------------------------------------------------------
+// Window (and menu items) identifiers management
+// ----------------------------------------------------------------------------
+
+namespace
+{
+
+// this array contains, in packed form, the "in use" flags for the entire
+// auto-generated ids range: N-th element of the array contains the flags for
+// ids in [wxID_AUTO_LOWEST + 8*N, wxID_AUTO_LOWEST + 8*N + 7] range
+//
+// initially no ids are in use and we allocate them consecutively, but after we
+// exhaust the entire range, we wrap around and reuse the ids freed in the
+// meanwhile
+wxByte gs_autoIdsInUse[(wxID_AUTO_HIGHEST - wxID_AUTO_LOWEST + 1)/8 + 1] = { 0 };
+
+// this is an optimization used until we wrap around wxID_AUTO_HIGHEST: if this
+// value is < wxID_AUTO_HIGHEST we know that we haven't wrapped yet and so can
+// allocate the ids simply by incrementing it
+static wxWindowID gs_nextControlId = wxID_AUTO_LOWEST;
+
+void MarkAutoIdUsed(wxWindowID id)
+{
+ id -= wxID_AUTO_LOWEST;
+
+ const int theByte = id / 8;
+ const int theBit = id % 8;
+
+ gs_autoIdsInUse[theByte] |= 1 << theBit;
+}
+
+void FreeAutoId(wxWindowID id)
+{
+ id -= wxID_AUTO_LOWEST;
+
+ const int theByte = id / 8;
+ const int theBit = id % 8;
+
+ gs_autoIdsInUse[theByte] &= ~(1 << theBit);
+}
+
+bool IsAutoIdInUse(wxWindowID id)
+{
+ id -= wxID_AUTO_LOWEST;
+
+ const int theByte = id / 8;
+ const int theBit = id % 8;
+
+ return (gs_autoIdsInUse[theByte] & (1 << theBit)) != 0;
+}
+
+} // anonymous namespace
+
+
+/* static */
+bool wxWindowBase::IsAutoGeneratedId(wxWindowID id)
+{
+ if ( id < wxID_AUTO_LOWEST || id > wxID_AUTO_HIGHEST )
+ return false;
+
+ // we shouldn't have any stray ids in this range
+ wxASSERT_MSG( IsAutoIdInUse(id), "unused automatically generated id?" );
+
+ return true;
+}
+
+wxWindowID wxWindowBase::NewControlId(int count)
+{
+ wxASSERT_MSG( count > 0, "can't allocate less than 1 id" );
+
+ if ( gs_nextControlId + count - 1 <= wxID_AUTO_HIGHEST )
+ {
+ // we haven't wrapped yet, so we can just grab the next count ids
+ wxWindowID id = gs_nextControlId;
+
+ while ( count-- )
+ MarkAutoIdUsed(gs_nextControlId++);
+
+ return id;
+ }
+ else // we've already wrapped or are now going to
+ {
+ // brute-force search for the id values
+
+ // number of consecutive free ids found so far
+ int found = 0;
+
+ for ( wxWindowID id = wxID_AUTO_LOWEST; id <= wxID_AUTO_HIGHEST; id++ )
+ {
+ if ( !IsAutoIdInUse(id) )
+ {
+ // found another consecutive available id
+ found++;
+ if ( found == count )
+ {
+ // mark all count consecutive free ids we found as being in
+ // use now and rewind back to the start of available range
+ // in the process
+ while ( count-- )
+ MarkAutoIdUsed(id--);
+
+ return id;
+ }
+ }
+ else // this id is in use
+ {
+ // reset the number of consecutive free values found
+ found = 0;
+ }
+ }
+ }
+
+ // if we get here, there are not enough consecutive free ids
+ return wxID_NONE;
+}
+
+void wxWindowBase::ReleaseControlId(wxWindowID id)
+{
+ wxCHECK_RET( IsAutoGeneratedId(id), "can't release non auto-generated id" );
+
+ FreeAutoId(id);
+}
projects / wxWidgets.git / blobdiff