Android Question About size of bitmap

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dreamworld

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• Oct 11, 2013

• #2

What's the unit of bitmap's width and height? Pixel?

 

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Informatix

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• Oct 11, 2013

• #3

All positions (X, Y) and dimensions (Width, Height) are in pixels.
100dip or 100%x are converted to pixels.

 

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dreamworld

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• Oct 11, 2013

• #4

do we need to convert the size of bitnap to dip, if we draw with its size?

Dim Bitmap1 As Bitmap Bitmap1.Initialize(File.DirAssets, "X.jpg") Dim DestRect As Rect DestRect.Initialize(0, 0, Bitmap1.Width, Bitmap1.Height) Canvas1.DrawBitmap(Bitmap1, Null, DestRect)

Or

DestRect.Initialize(0,0,Bitmap1.Width * 1dip, Bitmap1.Height * 1dip)

 

Last edited: Oct 12, 2013

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dreamworld

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• Oct 12, 2013

• #5

And when an imageview load a bitmap, can it automatically convert the size of the bitmap to dip before drawing it. In this case, we are unable to manually convert the size of the bitmap to dip, if the gravity is center.

 

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dreamworld

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• Oct 13, 2013

• #6

Erel?

 

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Erel

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• Oct 13, 2013

• #7

The width and height are measured in pixels. If you want to scale the image automatically then you need to explicitly set the ImageView width and height and set the Gravity to Fill.

 

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dreamworld

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• Oct 13, 2013

• #8

Which red line is better?

Dim Bitmap1 As Bitmap Bitmap1.Initialize(File.DirAssets, "X.jpg")
Dim DestRect As Rect

DestRect.Initialize(0, 0, Bitmap1.Width, Bitmap1.Height)
DestRect.Initialize(0, 0, Bitmap1.Width * 1dip, Bitmap1.Height * 1dip)

Canvas1.DrawBitmap(Bitmap1, Null, DestRect)

 

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Erel

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• Oct 13, 2013

• #9

It depends on what you are trying to achieve. If you want to stretch the image to always have the same (approximate) physical size then you should use:

B4X:

DestRect.Initialize(0, 0, Bitmap1.Width * 100dip / 100, Bitmap1.Height * 100dip / 100)

 

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dreamworld

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• Oct 13, 2013

• #10

why 100dip / 100?

100dip / 100 ≠ 1dip ?

 

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Erel

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• Oct 13, 2013

• #11

No. dip returns an integer value. So if the scale is 1.5 for example, 1dip will return 1. 100dip / 100 will return the correct value.
Another option is to use DipToCurrent keyword:

B4X:

Initialize(0,0, DipToCurrent(Bitmap1.Width), DipToCurrent(Bitmap.Height))

 

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