Thanks you very much for the response. Here is my understanding, let
me know in case his looks OK to you.
A. At the the boot time Andorid SDK (donut) prints below information
from the in the log which is coming from the file frameworks/base/libs/
ui/EGLDisplaySurface.cpp.
I/EGLDisplaySurface( 581): using (fd=21)
I/EGLDisplaySurface( 581): id =
I/EGLDisplaySurface( 581): xres = 320 px
I/EGLDisplaySurface( 581): yres = 480 px
I/EGLDisplaySurface( 581): xres_virtual = 320 px
I/EGLDisplaySurface( 581): yres_virtual = 960 px
I/EGLDisplaySurface( 581): bpp = 16
I/EGLDisplaySurface( 581): r = 11:5
I/EGLDisplaySurface( 581): g = 5:6
I/EGLDisplaySurface( 581): b = 0:5
I/EGLDisplaySurface( 581): width = 49 mm (165.877548 dpi)
I/EGLDisplaySurface( 581): height = 74 mm (164.756760 dpi)
I/EGLDisplaySurface( 581): refresh rate = 60.00 Hz
- File frameworks/base/libs/ui/EGLDisplaySurface.cpp uses
EGLDisplaySurface::mapFrameBuffer() to get a device_template and then
obtain a file descriptor fd out of it.
char const * const device_template[] = { "/dev/graphics/fb%u", "/
dev/fb%u", 0 };
int fd = -1; int i=0; char name[64];
while ((fd==-1) && device_template[i]) {
snprintf(name, 64, device_template[i], 0);
fd = open(name, O_RDWR, 0);
i++;
}
- Later on it populates the fix and variable screen infor in two
structures finfo and info.
struct fb_fix_screeninfo finfo;
if (ioctl(fd, FBIOGET_FSCREENINFO, &finfo) == -1)
return -errno;
struct fb_var_screeninfo info;
if (ioctl(fd, FBIOGET_VSCREENINFO, &info) == -1)
return -errno;
- Just incase the driver does not exhibit the heigth and width info it
takes some default value.
if (int(info.width) <= 0 || int(info.height) <= 0) {
// the driver doesn't return that information
// default to 160 dpi
info.width = ((info.xres * 25.4f)/160.0f + 0.5f);
info.height = ((info.yres * 25.4f)/160.0f + 0.5f);
}
- Finally it prints all the screen related informations in the log as
gatherd by finfo and info.
LOGI( "width = %d mm (%f dpi)\n" "height = %d mm
(%f dpi)\n" "refresh rate = %.2f Hz\n", info.width, xdpi,
info.height, ydpi, fps );
B. In this way point A reveals that
- As such Android SDK has no limitation for supporting the any screen
size whatever big or small.
- It the graphic driver which is mounted at /dev/graphics/ which will
expose its size and capabilities which is further read adn expedited
by Android SDK.
- My assumption here is the screen I am going to use can be mounted on
the Andoird {or say on Linux for now} and its drives will be able to
expose its size and capability. Of-course we can have some challenges
here, however that can be examined only when we have the setup of
details information about model and type of screen.
Thanks
Anand
On Sep 23, 11:35 pm, Dianne Hackborn <[email protected]> wrote:
> Your graphics driver needs to report the larger size, and the platform will
> use it. You can use the appropriate options in the emulator to see how it
> runs.
>
> Note that though the platform itself supports larger screens, little to now
> work has been done in the application or system UI to be optimized for such
> a screen.
>
>
>
> On Wed, Sep 23, 2009 at 11:18 AM, Anand <[email protected]> wrote:
>
> > Hi There,
>
> > I am not sure, if this is the correct platform to talk about it,
> > however I would like to know something about 'How Android supports the
> > large screen display'.
> > I mean here that suppose I want to port the Android SDK to a large
> > portable device having a large display as compared to HTC G1 mobile
> > screen, what all the OS modules (e.g surface manager, kernel: display
> > driver etc) I need to look upon/modify.
>
> > I guess what I am asking here is not a new subject as I can already
> > see by below links that the Android OS is ported for large screen
> > devices.
>
> > 1.http://www.icpdas-usa.com/vp_23a1.html:It has 3.5”/5.7” TFT LCD
> > and a rubber keypad.
>
> > Specifications & Additional Information
> > Models VP-23A1 VP-25A1
> > System Software
> > OS Android 1.5
> > SDK Provided Standard ViewPAC SDK for Windows and Linux by GNU C
> > language
> > CPU Module
> > CPU PXA270 or compatible (32-bit and 520 MHz)
> > SRAM 128 MB
>
> > 2. ARCHOS 5 Internet tablet shown on
>
> >http://www.marketwatch.com/story/archos-brings-the-android-platform-t...
> > and onhttp://www.archos.com/products/imt/index.html?country=in〈=en
> > as.
>
> > It has
> > • High resolution screen, 800x480 pixels, 4.8'' TFT LCD, 16 million
> > colors
> > • Touch screen
>
> > Let me know your opinion about it, any kind of clue will be
> > appreciated.
>
> > Regards,
> > Anand
>
> --
> Dianne Hackborn
> Android framework engineer
> [email protected]
>
> Note: please don't send private questions to me, as I don't have time to
> provide private support, and so won't reply to such e-mails. All such
> questions should be posted on public forums, where I and others can see and
> answer them.
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