_ICON - QB64 Wiki

_ICON

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The _ICON statement uses an image handle from _LOADIMAGE for the program header and icon image in the OS.


Contents

Syntax

_ICON [mainImageHandle&[, smallImageHandle&]]


Parameters

  • mainImageHandle& is the LONG handle value of the OS icon and title bar image pre-loaded with _LOADIMAGE when used alone.
  • smallImageHandle& is the LONG handle value of a different title bar image pre-loaded with _LOADIMAGE when used.
  • No image handle designates use of the default QB64 icon or the embedded icon set by $EXEICON.


Description

  • If no image handle is passed, the default QB64 icon will be used (all versions). If the $EXEICON metacommand is used, _ICON without an image handle uses the embedded icon from the binary (Windows only).
  • Beginning with version 1.000, the following is considered:
mainImageHandle& creates the image as the icon in the OS and the image in the program header (title bar).
smallImageHandle& can be used for a different image in the program header bar.
  • The header image will automatically be resized to fit the icon size of 16 X 16 if smaller or larger.
  • Once the program's icon is set, the image handle can be discarded with _FREEIMAGE.


Errors

  • NOTE: Icon files are not supported with _LOADIMAGE and an error will occur. See Example 2.
  • Images used can be smaller or larger than 32 X 32 pixels, but image resolution may be affected.
  • It is important to free unused or uneeded images with _FREEIMAGE to prevent memory overflow errors.
  • In SCREEN 0 (default text mode) you need to specify 32-bit mode in _LOADIMAGE to load images.


Examples

Example 1: Loading an image to a 32 bit palette in SCREEN 0 (the default screen mode).

i& =_LOADIMAGE("RDSWU16.BMP", 32) '<<<<<<< use your image file name here IF i& < -1 THEN _ICON i& _FREEIMAGE i& ' release image handle after setting icon END IF

Note: _ICON images can be freed if the SCREEN mode stays the same. Freed image handles can on longer be referenced.


Example 2: Function that converts an icon into a temporary bitmap for use in QB64. Function returns the available image count.

SCREEN _NEWIMAGE(640, 480, 256) _TITLE "Icon Converter" icon$ = "daphne.ico" '<<<<<<<<< change icon file name bitmap$ = "tempfile.bmp" indx% = 6 '1 minimum <<<<<<< higher values than count get highest entry image in icon file IF Icon2BMP(icon$, bitmap$, indx%) THEN img& = _LOADIMAGE(bitmap$) ' use 32 as color mode in SCREEN 0 IF img& < -1 THEN ' check that handle value is good before loading _ICON img& ' place image in header _PUTIMAGE (300, 250), img& 'place image on screen _FREEIMAGE img& ' always free unused handles to save memory KILL bitmap$ ' comment out and/or rename to save the bitmaps END IF END IF END ' ---------------------------------------------------- FUNCTION Icon2BMP% (filein AS STRING, fileout AS STRING, index AS INTEGER) 'function creates a bitmap of the icon and returns the icon count DIM byte AS _UNSIGNED _BYTE, word AS INTEGER, dword AS LONG DIM wide AS LONG, high AS LONG, BM AS INTEGER, bpp AS INTEGER rf = FREEFILE IF LCASE$(RIGHT$(filein, 4)) = ".ico" THEN 'check file extension is ICO only OPEN filein FOR BINARY ACCESS READ AS rf ELSE EXIT FUNCTION END IF GET rf, , word GET rf, , word: icon = word GET rf, , word: count = word IF icon <> 1 OR count = 0 THEN CLOSE rf: EXIT FUNCTION 'PRINT icon, count IF index > 0 AND index <= count THEN entry = 16 * (index - 1) ELSE entry = 16 * (count - 1) SEEK rf, 1 + 6 + entry 'start of indexed Entry header GET rf, , byte: wide = byte ' use this unsigned for images over 127 GET rf, , byte: high = byte ' use this unsigned because it isn't doubled GET rf, , word 'number of 4 BPP colors(256 & 32 = 0) & reserved bytes GET rf, , dword '2 hot spots both normally 0 in icons, used for cursors GET rf, , dword: size = dword 'this could be used, doesn't seem to matter GET rf, , dword: offset = dword 'find where the specific index BMP header is 'PRINT wide; "X"; high, size, offset SEEK rf, 1 + offset + 14 'only read the BPP in BMP header GET rf, , word: bpp = word IF bpp = 0 THEN CLOSE rf: EXIT FUNCTION IF bpp <= 24 THEN pixelbytes = bpp / 8 ELSE pixelbytes = 3 IF bpp > 1 AND bpp <= 8 THEN palettebytes = 4 * (2 ^ bpp) ELSE palettebytes = 0 datasize& = (wide * high * pixelbytes) + palettebytes 'no padder should be necessary filesize& = datasize& + 14 + 40 ' data and palette + header bmpoffset& = palettebytes + 54 ' data offset from start of bitmap readbytes& = datasize& + 28 ' (40 - 12) bytes left to read in BMP header and XOR mask only 'PRINT bpp, bmpoffset&, filesize& BM = CVI("BM") 'this will create "BM" in file like MKI$ would wf = FREEFILE OPEN fileout FOR BINARY AS wf PUT wf, , BM PUT wf, , filesize& dword = 0 PUT wf, , dword PUT wf, , bmpoffset& 'byte location of end of palette or BMP header dword = 40 PUT wf, , dword ' start of 40 byte BMP header PUT wf, , wide PUT wf, , high SEEK rf, 1 + offset + 12 ' after 12 bytes start copy of BMP header starting at planes dat$ = STRING$(readbytes&, 0) 'create string to hold remaining bytes needed w/o AND mask data GET rf, , dat$ ' copy lower header, palette(if used) and XOR mask PUT wf, , dat$ ' put all of the string data in the bitmap all at once CLOSE rf, wf Icon2BMP = count ' return the number of icons available in the icon file END FUNCTION

Code by Ted Weissgerber
Note: Once the file has been loaded into memory, the image handle can still be used even after the file has been deleted.


See also



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