Listview Q0
Dimitrie O. Paun
dpaun at rogers.com
Sat Oct 12 10:49:35 CDT 2002
This one starts the job of completing the item iterator
interface. I know now where I want to end up, so there's
a bit mode work to complete it, but the fundamental parts
are done with this patch. It also adds docu that may be
of interest to people following the listview.
Alexandre, do not commit the Q* series just yet. I want to get a
few more in (to finish the iterator work).
ChageLog
Iterator updates:
Add the notion of a special item which sits at the start of the list
Add the ability to iterate in both directions through the list
Document the iterator interface
Remove iterator_visibleitems
Rename iterator_clippeditems to iterator_visibleitems for consitency
Use the new bidirectionality to paint the items in decreasing order
Index: dlls/comctl32/listview.c
===================================================================
RCS file: /var/cvs/wine/dlls/comctl32/listview.c,v
retrieving revision 1.224
diff -u -r1.224 listview.c
--- dlls/comctl32/listview.c 11 Oct 2002 23:34:32 -0000 1.224
+++ dlls/comctl32/listview.c 12 Oct 2002 15:35:09 -0000
@@ -51,9 +51,6 @@
* these differences cause problems):
* LVM_INSERTITEM issues LVM_SETITEMSTATE and LVM_SETITEM in certain cases.
* LVM_SETITEM does not always issue LVN_ITEMCHANGING/LVN_ITEMCHANGED.
- * WM_PAINT does LVN_GETDISPINFO in item order 0->n, native does n->0.
- * WM_SETREDRAW(True) native does LVN_GETDISPINFO for all items and
- * does *not* invoke DefWindowProc
* WM_CREATE does not issue WM_QUERYUISTATE and associated registry
* processing for "USEDOUBLECLICKTIME".
*/
@@ -112,6 +109,7 @@
typedef struct tagITERATOR
{
INT nItem;
+ INT nSpecial;
RANGE range;
HDPA ranges;
INT index;
@@ -712,27 +710,143 @@
static BOOL ranges_del(HDPA ranges, RANGE range);
static void ranges_dump(HDPA ranges);
+/***
+ * ITERATOR DOCUMENTATION
+ *
+ * The iterator functions allow for easy, and convenient iteration
+ * over items of iterest in the list. Typically, you create a
+ * iterator, use it, and destroy it, as such:
+ * ITERATOR i;
+ *
+ * iterator_xxxitems(&i, ...);
+ * while (iterator_{prev,next}(&i)
+ * {
+ * //code which uses i.nItem
+ * }
+ * iterator_destroy(&i);
+ *
+ * where xxx is either: framed, or visible.
+ * Note that it is important that the code destroys the iterator
+ * after it's done with it, as the creation of the iterator may
+ * allocate memory, which thus needs to be freed.
+ *
+ * You can iterate both forwards, and backwards through the list,
+ * by using iterator_next or iterator_prev respectively.
+ *
+ * Lower numbered items are draw on top of higher number items in
+ * LVS_ICON, and LVS_SMALLICON (which are the only modes where
+ * items may overlap). So, to test items, you should use
+ * iterator_next
+ * which lists the items top to bottom (in Z-order).
+ * For drawing items, you should use
+ * iterator_prev
+ * which lists the items bottom to top (in Z-order).
+ * If you keep iterating over the items after the end-of-items
+ * marker (-1) is returned, the iterator will start from the
+ * beginning. Typically, you don't need to test for -1,
+ * because iterator_{next,prev} will return TRUE if more items
+ * are to be iterated over, or FALSE otherwise.
+ *
+ * Note: the iterator is defined to be bidirectional. That is,
+ * any number of prev followed by any number of next, or
+ * five versa, should leave the iterator at the same item:
+ * prev * n, next * n = next * n, prev * n
+ *
+ * The iterator has a notion of a out-of-order, special item,
+ * which sits at the start of the list. This is used in
+ * LVS_ICON, and LVS_SMALLICON mode to handle the focused item,
+ * which needs to be first, as it may overlap other items.
+ *
+ * The code is a bit messy because we have:
+ * - a special item to deal with
+ * - simple range, or composite range
+ * - empty range.
+ * If find bugs, or want to add features, please make sure you
+ * always check/modify *both* iterator_prev, and iterator_next.
+ */
+
+/****
+ * This function iterates through the items in increasing order,
+ * but prefixed by the special item, then -1. That is:
+ * special, 1, 2, 3, ..., n, -1.
+ * Each item is listed only once.
+ */
static inline BOOL iterator_next(ITERATOR* i)
{
if (i->nItem == -1)
{
- if (i->ranges) goto pickarange;
- return (i->nItem = i->range.lower) != -1;
+ i->nItem = i->nSpecial;
+ if (i->nItem != -1) return TRUE;
}
+ if (i->nItem == i->nSpecial)
+ {
+ if (i->ranges) i->index = 0;
+ goto pickarange;
+ }
+
i->nItem++;
- if (i->nItem <= i->range.upper)
- return TRUE;
+testitem:
+ if (i->nItem == i->nSpecial) i->nItem++;
+ if (i->nItem <= i->range.upper) return TRUE;
pickarange:
- if (i->ranges && i->index < i->ranges->nItemCount)
+ if (i->ranges)
{
- i->range = *(RANGE*)DPA_GetPtr(i->ranges, i->index++);
- return (i->nItem = i->range.lower) != -1;
+ if (i->index < i->ranges->nItemCount)
+ i->range = *(RANGE*)DPA_GetPtr(i->ranges, i->index++);
+ else goto end;
}
- i->nItem = i->range.lower = i->range.upper = -1;
+ else if (i->nItem > i->range.upper) goto end;
+
+ i->nItem = i->range.lower;
+ if (i->nItem >= 0) goto testitem;
+end:
+ i->nItem = -1;
return FALSE;
}
+/****
+ * This function iterates through the items in decreasing order,
+ * followed by the special item, then -1. That is:
+ * n, n-1, ..., 3, 2, 1, special, -1.
+ * Each item is listed only once.
+ */
+static inline BOOL iterator_prev(ITERATOR* i)
+{
+ BOOL start = FALSE;
+
+ if (i->nItem == -1)
+ {
+ start = TRUE;
+ if (i->ranges) i->index = i->ranges->nItemCount;
+ goto pickarange;
+ }
+ if (i->nItem == i->nSpecial)
+ {
+ i->nItem = -1;
+ return FALSE;
+ }
+
+ i->nItem--;
+testitem:
+ if (i->nItem == i->nSpecial) i->nItem--;
+ if (i->nItem >= i->range.lower) return TRUE;
+
+pickarange:
+ if (i->ranges)
+ {
+ if (i->index > 0)
+ i->range = *(RANGE*)DPA_GetPtr(i->ranges, --i->index);
+ else goto end;
+ }
+ else if (!start && i->nItem < i->range.lower) goto end;
+
+ i->nItem = i->range.upper;
+ if (i->nItem >= 0) goto testitem;
+end:
+ return (i->nItem = i->nSpecial) != -1;
+}
+
static RANGE iterator_range(ITERATOR* i)
{
RANGE range;
@@ -744,18 +858,27 @@
return range;
}
+/***
+ * Releases resources associated with this ierator.
+ */
static inline void iterator_destroy(ITERATOR* i)
{
if (i->ranges) DPA_Destroy(i->ranges);
}
+/***
+ * Create an empty iterator.
+ */
static inline BOOL iterator_empty(ITERATOR* i)
{
ZeroMemory(i, sizeof(*i));
- i->nItem = i->range.lower = i->range.upper = -1;
+ i->nItem = i->nSpecial = i->range.lower = i->range.upper = -1;
return TRUE;
}
+/***
+ * Creates an iterator over the items which intersect lprc.
+ */
static BOOL iterator_frameditems(ITERATOR* i, LISTVIEW_INFO* infoPtr, const RECT* lprc)
{
UINT uView = infoPtr->dwStyle & LVS_TYPEMASK;
@@ -803,7 +926,10 @@
return TRUE;
}
-static BOOL iterator_clippeditems(ITERATOR* i, LISTVIEW_INFO *infoPtr, HDC hdc)
+/***
+ * Creates an iterator over the items which intersect the visible region of hdc.
+ */
+static BOOL iterator_visibleitems(ITERATOR* i, LISTVIEW_INFO *infoPtr, HDC hdc)
{
POINT Origin, Position;
RECT rcItem, rcClip;
@@ -814,7 +940,7 @@
if (!iterator_frameditems(i, infoPtr, &rcClip)) return FALSE;
if (rgntype == SIMPLEREGION) return TRUE;
- /* if we can't deal with the region, we'll just go with the simple range */
+ /* if we can't deal with the region, we'll just go with the simple range */
if (!LISTVIEW_GetOrigin(infoPtr, &Origin)) return TRUE;
if (!(i->ranges = DPA_Create(10))) return TRUE;
if (!ranges_add(i->ranges, i->range))
@@ -824,7 +950,7 @@
return TRUE;
}
- /* no delete the invisible items from the list */
+ /* now delete the invisible items from the list */
for (nItem = i->range.lower; nItem <= i->range.upper; nItem++)
{
if (!LISTVIEW_GetItemListOrigin(infoPtr, nItem, &Position)) continue;
@@ -842,11 +968,6 @@
return TRUE;
}
-static inline BOOL iterator_visibleitems(ITERATOR* i, LISTVIEW_INFO *infoPtr)
-{
- return iterator_frameditems(i, infoPtr, &infoPtr->rcList);
-}
-
/******** Misc helper functions ************************************/
static inline LRESULT CallWindowProcT(WNDPROC proc, HWND hwnd, UINT uMsg,
@@ -1281,7 +1402,7 @@
{
ITERATOR i;
- iterator_visibleitems(&i, infoPtr);
+ iterator_frameditems(&i, infoPtr, &infoPtr->rcList);
while(iterator_next(&i))
{
if (LISTVIEW_GetItemState(infoPtr, i.nItem, LVIS_SELECTED))
@@ -3238,7 +3359,7 @@
if (!LISTVIEW_GetOrigin(infoPtr, &Origin)) return;
/* figure out what we need to draw */
- iterator_clippeditems(&i, infoPtr, hdc);
+ iterator_visibleitems(&i, infoPtr, hdc);
/* send cache hint notification */
if (infoPtr->dwStyle & LVS_OWNERDATA)
@@ -3252,7 +3373,7 @@
}
/* iterate through the invalidated rows */
- while(iterator_next(&i))
+ while(iterator_prev(&i))
{
item.iItem = i.nItem;
item.iSubItem = 0;
@@ -3344,13 +3465,13 @@
}
/* figure out what we need to draw */
- iterator_clippeditems(&i, infoPtr, hdc);
+ iterator_visibleitems(&i, infoPtr, hdc);
/* a last few bits before we start drawing */
TRACE("Colums=(%di - %d)\n", nFirstCol, nLastCol);
/* iterate through the invalidated rows */
- while(iterator_next(&i))
+ while(iterator_prev(&i))
{
nDrawPosY = i.nItem * infoPtr->nItemHeight;
@@ -3404,9 +3525,9 @@
if (!LISTVIEW_GetOrigin(infoPtr, &Origin)) return;
/* figure out what we need to draw */
- iterator_clippeditems(&i, infoPtr, hdc);
+ iterator_visibleitems(&i, infoPtr, hdc);
- while(iterator_next(&i))
+ while(iterator_prev(&i))
{
if (!LISTVIEW_GetItemListOrigin(infoPtr, i.nItem, &Position)) continue;
Position.x += Origin.x;
@@ -3439,9 +3560,9 @@
if (!LISTVIEW_GetOrigin(infoPtr, &Origin)) return;
/* figure out what we need to draw */
- iterator_clippeditems(&i, infoPtr, hdc);
+ iterator_visibleitems(&i, infoPtr, hdc);
- while(iterator_next(&i))
+ while(iterator_prev(&i))
{
if (LISTVIEW_GetItemState(infoPtr, i.nItem, LVIS_FOCUSED))
continue;
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