Qt-jambi-interest Archive, December 2006
Qwt?
Message 1 in thread
Hello,
Would it be possible to wrap popular Qt based libraries like Qwt to
Jambi with the generator? For instance QwtArrayData
(http://qwt.sourceforge.net/class_qwt_array_data.html) takes two
pointers to double for the initialization, how would this be
wrapped to Java code?
Best regards,
Helge Fredriksen
Message 2 in thread
Helge Fredriksen wrote:
> Hello,
>
> Would it be possible to wrap popular Qt based libraries like Qwt to
> Jambi with the generator?
Hi Helge,
We haven't explicitly tried Qwt, but it should be possible.
> For instance QwtArrayData
> (http://qwt.sourceforge.net/class_qwt_array_data.html) takes two
> pointers to double for the initialization, how would this be
> wrapped to Java code?
You would use QNativePointer for this. QNativePointer is when pointer
types arise in C++ that can not be represented in Java. You would create
an array type native pointer (with size) and initialize it with our
data. Something along the lines of:
// Construct the double * of size xArray.length
QNativePointer x =
new QNativePointer(QNativePointer.Type.Double, xArray.length);
// Copy the data over...
for (int i = 0; i<xArray.length; ++i)
x.setDoubleAt(i, xArray[i]);
// Similar for y
QwtArrayData data = new QwtArrayData(x, y, size);
---
The native array is memory managed by the GC so you need to keep a
reference to x for the lifetime of data. Alternativly, if data takes
ownership of the native memory, you can disable the memory management of
the array by calling:
setAutoDeleteMode(QNativePointer.AutoDeleteMode.None);
-
best regards,
Gunnar
