/////////////////////////////////////////////////////////////////////////////
// Name: wx/private/menuradio.h
// Purpose: wxMenuRadioItemsData implementation
// Author: Vadim Zeitlin
// Modified: Artur Wieczorek: added UpdateOnInsertNonRadio()
// Created: 2017-08-12
// Copyright: (c) 2011 Vadim Zeitlin et al
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef WX_PRIVATE_MENURADIO_H_
#define WX_PRIVATE_MENURADIO_H_
#include "wx/vector.h"
// Contains the data about the radio items groups in the given menu.
class wxMenuRadioItemsData
{
public:
wxMenuRadioItemsData() { }
// Default copy ctor, assignment operator and dtor are all ok.
// Find the start and end of the group containing the given position or
// return false if it's not inside any range.
bool GetGroupRange(int pos, int *start, int *end) const
{
// We use a simple linear search here because there are not that many
// items in a menu and hence even fewer radio items ranges anyhow, so
// normally there is no need to do anything fancy (like keeping the
// array sorted and using binary search).
for ( Ranges::const_iterator it = m_ranges.begin();
it != m_ranges.end();
++it )
{
const Range& r = *it;
if ( r.start <= pos && pos <= r.end )
{
if ( start )
*start = r.start;
if ( end )
*end = r.end;
return true;
}
}
return false;
}
// Take into account the new radio item about to be added at the given
// position. The are two cases to handle:
// - If item precedes the range, the range indices have to be updated.
// - If item falls inside the range, this range is extended to include
// the item.
// Returns true if this item starts a new radio group, false if it extends
// an existing one.
bool UpdateOnInsertRadio(int pos)
{
bool inExistingGroup = false;
for ( Ranges::iterator it = m_ranges.begin();
it != m_ranges.end();
++it )
{
Range& r = *it;
if ( pos < r.start )
{
// Item is inserted before this range, update its indices.
r.start++;
r.end++;
}
else if ( pos <= r.end + 1 )
{
wxASSERT_MSG(!inExistingGroup,
wxS("Item already inserted inside another range"));
// Item is inserted in the middle of this range or immediately
// after it in which case it extends this range so make it span
// one more item in any case.
r.end++;
inExistingGroup = true;
}
//else: Item is inserted after this range, nothing to do for it.
}
if ( inExistingGroup )
return false;
// Make a new range for the group this item will belong to.
Range r;
r.start = pos;
r.end = pos;
m_ranges.push_back(r);
return true;
}
// Take into account the new non-radio item about to be added at the given
// position. The are two cases to handle:
// - If item precedes the range, the range indices have to be updated.
// - If item falls inside the range, this range has to be split into
// two new ranges.
// Returns true if existing group has been split into two subgroups.
bool UpdateOnInsertNonRadio(int pos)
{
bool wasSplit = false;
Range newRange;
for ( Ranges::iterator it = m_ranges.begin();
it != m_ranges.end();
++it )
{
Range& r = *it;
if ( pos <= r.start )
{
// Item is inserted before this range or just at its start,
// update its indices.
r.start++;
r.end++;
}
else if ( pos <= r.end )
{
wxASSERT_MSG(!wasSplit,
wxS("Item already inserted inside another range"));
// Item is inserted inside this range in which case
// it breaks the range into two parts: one ending before
// the item and one started after it.
// The new range after the item has to be stored and added to the list
// after finishing the iteration through the ranges.
newRange.start = pos + 1; // start after the item
newRange.end = r.end + 1; // inherits current end "moved up" by one item
wasSplit = true;
// Current range ends just before the item position.
r.end = pos - 1;
}
//else: Item is inserted after this range, nothing to do for it.
}
if ( !wasSplit )
return false;
// Add a split range to the list.
m_ranges.push_back(newRange);
return true;
}
// Update the ranges of the existing radio groups after removing the menu
// item at the given position.
//
// The item being removed can be the item of any kind, not only the radio
// button belonging to the radio group, and this function checks for it
// and, as a side effect, returns true if this item was found inside an
// existing radio group.
bool UpdateOnRemoveItem(int pos)
{
bool inExistingGroup = false;
// Pointer to (necessarily unique) empty group which could be left
// after removing the last radio button from it.
Ranges::iterator itEmptyGroup = m_ranges.end();
for ( Ranges::iterator it = m_ranges.begin();
it != m_ranges.end();
++it )
{
Range& r = *it;
if ( pos < r.start )
{
// Removed item was positioned before this range, update its
// indices.
r.start--;
r.end--;
}
else if ( pos <= r.end )
{
// Removed item belongs to this radio group (it is a radio
// button), update index of its end.
r.end--;
// Check if empty group left after removal.
// If so, it will be deleted later on.
if ( r.end < r.start )
itEmptyGroup = it;
inExistingGroup = true;
}
//else: Removed item was after this range, nothing to do for it.
}
// Remove empty group from the list.
if ( itEmptyGroup != m_ranges.end() )
m_ranges.erase(itEmptyGroup);
return inExistingGroup;
}
private:
// Contains the inclusive positions of the range start and end.
struct Range
{
int start;
int end;
};
typedef wxVector<Range> Ranges;
Ranges m_ranges;
};
#endif // WX_PRIVATE_MENURADIO_H_
