How to find TImage picture left
lazarus / 39-Graphics

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hello2hello · 2014-06-26 11:50

What I want to know is the left of the picture ( or canvas am unsure
of the call ) within a TImage. The pictures attached demonstrate what
information I need.

The first picture is without the picture centered whereas the second
is. It "moves" the picture to the center of the image.

So I would like to know the left of the picture itself (not Image1),
if I can access the width of the picture (not Image1) that would
suffice.

All in all the second picture where it says "what's this distance" is
what I need to know.

I cannot use Image1.picture.bitmap.width either due to the pixels per
that picture e.g 1024x768 the size of my image may only be 800x600
thus the bitmap width would be 1024 yet I need to know the 600. My
image size cannot not be the exact size of the bitmap supplied.

If unclear I will try to better word this

P.S I apologise in advance if this is a simple question and has been
answered before but I couldn't think of any other words to put into a
search

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wp · 2014-06-26 12:06

Code: [Select]  ThisDistance := (Image1.Width - Image1.Picture.Width)
div 2;

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hello2hello · 2014-06-26 12:15

Hi Wp,

For some reason when I tried that before it didn't work, worked
perfectly this time thank you very much.

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hello2hello · 2014-06-26 15:53

I've been experimenting with the Image.picture.Width and have found
that it does not change when the width of the picture changes?

if I change the Image width manually in the IDE I would expect
image.picture.width would change or is this accessing something else?

My questions are

Is the picture.width defined when the picture is loaded from file?
When is the picture.width changed?

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wp · 2014-06-26 16:11

Sorry for confusing you: My former posting assumed a non-stretched
image. If the image is stretched the Image1.DestRect contains the
rectangle covered by the stretched image (I guess...). Therefore:

Code: [Select]  ThisDistance := (Image1.Width - (Image1.DestRect.Right
- Image1.DestRect.Left)) div 2;

The Image.Picture.Width is the width of the image as it is written in
the file (like bitmap.Width). The Image.Width, on the other hand, is
the width of the control in the form.

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hello2hello · 2014-06-26 16:52

Wonderful, Exactly what I wanted

Thank you very much wp