1<html><head><base target=k-main></head><body bgcolor=white> 2 3<font face=Times size=3> 4 5A custom view is a view which can be accessed like any other view, using 6row and property operations, but which is fully managed by a customized 7"viewer" class. The viewer will eventually handle all requests for the 8view, such as defining its structure and size, as well as providing the 9actual data values when requested. 10<P> 11 12Custom views are read-only in this version, and cannot propagate changes. 13<P> 14 15To implement a custom view, you must derive your viewer from this base 16class and define each of the virtual members. Then create a new object 17of this type on the heap and pass it to the <A HREF="c4_View.html" >c4_View</A> constructor. Your 18viewer will automatically be destroyed when the last reference to its 19view goes away. See the DBF2MK sample code for an example of a viewer. 20 21<P> 22 23 24 25<hr size=1> 26 27<dl> 28 29 <if !private> 30 <a name="c4_CustomViewer_GetItem_intintc4_Bytes___"><dt> 31 <nobr> 32 virtual bool 33 <b>GetItem</b> (int row_, int col_, <A HREF="c4_Bytes.html" >c4_Bytes</A>& buf_); 34 </nobr> 35 <dd> 36 37 38 <font face=Helvetica size=-1>Fetch one data item, return it as a generic data value</font> 39 <p> 40 41 42 <if !private> 43 <a name="c4_CustomViewer_GetSize___"><dt> 44 <nobr> 45 virtual int 46 <b>GetSize</b> (); 47 </nobr> 48 <dd> 49 50 51 <font face=Helvetica size=-1>Return the number of rows in this view</font> 52 <p> 53 54 55 <if !private> 56 <a name="c4_CustomViewer_GetTemplate___"><dt> 57 <nobr> 58 virtual <A HREF="c4_View.html" >c4_View</A> 59 <b>GetTemplate</b> (); 60 </nobr> 61 <dd> 62 63 64 <font face=Helvetica size=-1>Return the structure of this view (initialization, called once)</font> 65 <p> 66 67 68 <if !private> 69 <a name="c4_CustomViewer_c4_CustomViewer__"><dt> 70 <nobr> 71 72 <b>c4_CustomViewer</b> (); 73 </nobr> 74 <dd> 75 76 77 <font face=Helvetica size=-1>Constructor, must be overriden in derived class</font> 78 <p> 79 80 81 <if !private> 82 <a name="c4_CustomViewer__c4_CustomViewer___"><dt> 83 <nobr> 84 virtual 85 <b>~c4_CustomViewer</b> (); 86 </nobr> 87 <dd> 88 89 90 <font face=Helvetica size=-1>Destructor</font> 91 <p> 92 93 94</dl> 95 96<hr size=1 width=50 align=left> 97class 98<b>c4_CustomViewer</b> 99</font> 100 101</body></html> 102