ViewPort Properties

**Kapil** · 17th March 2006, 11:14

Hi,

I have a big design which i have to draw using QT. Now drawing the entire design dynamically and displaying it on the frame takes lots of time.
This application is very time specific.
So what i planned is using the viewport concept wherein only that part of the design is dynamically created which is currently in display on the window. If the user moves the design left to right or vice versa and up to down or vice versa then the part of window is recreated dynamically into design.
This concept would save me time from drawing the entire design again n again.

Can this be implemented using QT?
Can we use the viewport concept in QT?

Thanking you,

with regards,
Kapil

**jacek** · 17th March 2006, 11:31

You could try Q3Canvas or implement something similar yourself.

**Kapil** · 20th March 2006, 09:21

Hi,

I went thru the QCanvas class definition but then which of the function can provide me with the functionality of View Port.

I do not want to show the entire picture 'coz my image file which is dynamically generated is very Big and takes long CPU time to get executed.
So i just want to create that part of image which is currently on display on screen dynamically.

Moment the user scrolls from left to right or top to bottom, the image for the new region gets created. This helps me from saving major time of execution.

I could not locate any similar function in QCanvas which could help me in it.

Kapil

**jacek** · 20th March 2006, 15:41

QCanvas draws only those items that are visible.

**Kapil** · 22nd March 2006, 05:06

Hi,

i tried using the qcanvas but it gives the error that "qcanvas.h" not found.. i checked in the include folder where i have installed QT and actually there were no qcanvas and related header files present...

I am using the opensource windows version of QT4.1.1 with mingw...

I dont know from where to get the entire package of QCanvas header files...

please tell me how can i get them..

Kapil