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the_20extended_20combobox [2018/03/31 13:19] – external edit 127.0.0.1the_20extended_20combobox [2024/01/05 00:21] (current) – external edit 127.0.0.1
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 ===== Initialisation ===== ===== Initialisation =====
 \\  To start off with we need to include this initialisation code:\\ \\  \\  To start off with we need to include this initialisation code:\\ \\ 
 +<code bb4w>
         DIM icex{dwSize%, dwICC%}         DIM icex{dwSize%, dwICC%}
         ICC_USEREX_CLASSES = &200         ICC_USEREX_CLASSES = &200
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         icex.dwICC% = ICC_USEREX_CLASSES         icex.dwICC% = ICC_USEREX_CLASSES
         SYS "InitCommonControlsEx", icex{}         SYS "InitCommonControlsEx", icex{}
 +</code>
 \\  \\ 
 ===== Image lists ===== ===== Image lists =====
 \\  The set of images to be used in the extended combobox must be supplied as an //image list//. The first step is to create an empty image list as follows:\\ \\  \\  The set of images to be used in the extended combobox must be supplied as an //image list//. The first step is to create an empty image list as follows:\\ \\ 
 +<code bb4w>
         dx% = 16         dx% = 16
         dy% = 16         dy% = 16
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         SYS "ImageList_Create", dx%, dy%, 0, maximages%, 0 TO himglist%         SYS "ImageList_Create", dx%, dy%, 0, maximages%, 0 TO himglist%
         IF himglist% = 0 ERROR 100, "Couldn't create image list"         IF himglist% = 0 ERROR 100, "Couldn't create image list"
 +</code>
 Here **dx%** and **dy%** are the width and height, respectively, of each image in pixels and **maximages%** is the maximum number of images that the image list will ever need to hold.\\ \\  The next step is to //populate// the image list with images. You can do that either from a set of individual bitmaps or from one or more image //strips// (or a mixture of the two). An image strip is a bitmap containing several identical-sized images side-by-side.\\ \\  For the purposes of this example I will use the bitmap file **WIDGETS.BMP** supplied with BBC BASIC for Windows; this contains five 24x24 images in a strip 120 pixels wide by 24 pixels high. Since these images are a little on the large size for use in a combobox the bitmap can be resized when it is loaded, thus:\\ \\  Here **dx%** and **dy%** are the width and height, respectively, of each image in pixels and **maximages%** is the maximum number of images that the image list will ever need to hold.\\ \\  The next step is to //populate// the image list with images. You can do that either from a set of individual bitmaps or from one or more image //strips// (or a mixture of the two). An image strip is a bitmap containing several identical-sized images side-by-side.\\ \\  For the purposes of this example I will use the bitmap file **WIDGETS.BMP** supplied with BBC BASIC for Windows; this contains five 24x24 images in a strip 120 pixels wide by 24 pixels high. Since these images are a little on the large size for use in a combobox the bitmap can be resized when it is loaded, thus:\\ \\ 
 +<code bb4w>
         nimages% = 5         nimages% = 5
         bmpfile$ = @lib$+"..\examples\windows\widgets.bmp"         bmpfile$ = @lib$+"..\examples\windows\widgets.bmp"
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         SYS "LoadImage", 0, bmpfile$, 0, dx%*nimages%, dy%, LR_LOADFROMFILE TO hbitmap%         SYS "LoadImage", 0, bmpfile$, 0, dx%*nimages%, dy%, LR_LOADFROMFILE TO hbitmap%
         IF hbitmap% = 0 ERROR 100, "Couldn't load bitmap file"         IF hbitmap% = 0 ERROR 100, "Couldn't load bitmap file"
 +</code>
 Now it is straightforward to populate the first five images in the image list from the bitmap:\\ \\  Now it is straightforward to populate the first five images in the image list from the bitmap:\\ \\ 
 +<code bb4w>
         SYS "ImageList_Add", himglist%, hbitmap%, 0         SYS "ImageList_Add", himglist%, hbitmap%, 0
         SYS "DeleteObject", hbitmap%         SYS "DeleteObject", hbitmap%
 +</code>
 More images (or strips) can be added, up to the limit specified when the image list was created, using further calls to **ImageList_Add**.\\ \\  Now the image list is ready we can concentrate on creating the extended combobox itself. The process depends on whether you want to display the combobox in a dialogue box or directly on your program's main window.\\ \\  More images (or strips) can be added, up to the limit specified when the image list was created, using further calls to **ImageList_Add**.\\ \\  Now the image list is ready we can concentrate on creating the extended combobox itself. The process depends on whether you want to display the combobox in a dialogue box or directly on your program's main window.\\ \\ 
 ===== Dialogue box ===== ===== Dialogue box =====
 \\  As usual, we must install the appropriate library for working with dialogue boxes:\\ \\  \\  As usual, we must install the appropriate library for working with dialogue boxes:\\ \\ 
 +<code bb4w>
         INSTALL @lib$+"WINLIB2"         INSTALL @lib$+"WINLIB2"
 +</code>
 (alternatively install **WINLIB2A** or **WINLIB2B** if you need the facilities they provide).\\ \\  Now we will create a simple dialogue box containing just a cancel button and the extended combobox:\\ \\  (alternatively install **WINLIB2A** or **WINLIB2B** if you need the facilities they provide).\\ \\  Now we will create a simple dialogue box containing just a cancel button and the extended combobox:\\ \\ 
 +<code bb4w>
         dlg% = FN_newdialog("Extended combobox", 250, 20, 150, 140, 8, 1000)         dlg% = FN_newdialog("Extended combobox", 250, 20, 150, 140, 8, 1000)
         PROC_pushbutton(dlg%, "Cancel", 2, 20, 120, 56, 14, 0)         PROC_pushbutton(dlg%, "Cancel", 2, 20, 120, 56, 14, 0)
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         \            WS_VSCROLL OR CBS_AUTOHSCROLL OR CBS_DROPDOWN, \         \            WS_VSCROLL OR CBS_AUTOHSCROLL OR CBS_DROPDOWN, \
         \            "ComboBoxEx32")         \            "ComboBoxEx32")
 +</code>
 Note that the combobox has been allocated the ID number **101**. Refer to the documentation for [[http://www.bbcbasic.co.uk/bbcwin/manual/bbcwing.html#dlgitem|PROC_dlgitem]] for the meaning of the other parameters. \\ \\  The dialogue box is displayed in the usual way:\\ \\  Note that the combobox has been allocated the ID number **101**. Refer to the documentation for [[http://www.bbcbasic.co.uk/bbcwin/manual/bbcwing.html#dlgitem|PROC_dlgitem]] for the meaning of the other parameters. \\ \\  The dialogue box is displayed in the usual way:\\ \\ 
 +<code bb4w>
         PROC_showdialog(dlg%)         PROC_showdialog(dlg%)
 +</code>
 We've now created the dialogue box and the extended combobox, but the combobox is still empty. The next step is to tell the combobox which image list to use:\\ \\  We've now created the dialogue box and the extended combobox, but the combobox is still empty. The next step is to tell the combobox which image list to use:\\ \\ 
 +<code bb4w>
         CBEM_SETIMAGELIST = &402         CBEM_SETIMAGELIST = &402
         SYS "SendDlgItemMessage", !dlg%, cbid%, CBEM_SETIMAGELIST, 0, himglist%         SYS "SendDlgItemMessage", !dlg%, cbid%, CBEM_SETIMAGELIST, 0, himglist%
 +</code>
 Note the use of the combobox's ID number **cbid%**.\\ \\  To add items to the combobox we first have to declare some constants and a data structure:\\ \\  Note the use of the combobox's ID number **cbid%**.\\ \\  To add items to the combobox we first have to declare some constants and a data structure:\\ \\ 
 +<code bb4w>
         CBEIF_TEXT = 1         CBEIF_TEXT = 1
         CBEIF_IMAGE = 2         CBEIF_IMAGE = 2
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         DIM cbxi{mask%, iItem%, pszText%, cchTextMax%, iImage%, iSelectedImage%, \         DIM cbxi{mask%, iItem%, pszText%, cchTextMax%, iImage%, iSelectedImage%, \
         \        iOverlay%, iIndent%, lParam}         \        iOverlay%, iIndent%, lParam}
 +</code>
 Now we can define each item as follows:\\ \\  Now we can define each item as follows:\\ \\ 
 +<code bb4w>
           text$ = "Combobox item"+CHR$0           text$ = "Combobox item"+CHR$0
           cbxi.mask% = CBEIF_TEXT OR CBEIF_IMAGE OR CBEIF_SELECTEDIMAGE           cbxi.mask% = CBEIF_TEXT OR CBEIF_IMAGE OR CBEIF_SELECTEDIMAGE
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           cbxi.iSelectedImage% = imageno%           cbxi.iSelectedImage% = imageno%
           SYS "SendDlgItemMessage", !dlg%, cbid%, CBEM_INSERTITEMA, 0, cbxi{}           SYS "SendDlgItemMessage", !dlg%, cbid%, CBEM_INSERTITEMA, 0, cbxi{}
 +</code>
 Here **itemno%** is the item to define (starting at zero for the first item), **imageno%** is the image to display alongside the text (zero for the first image in the image list) and **text$** is the text for this item. Note particularly the **CHR$0** termination for the text string. You can set **itemno%** to the special value **-1**, which adds it at the end of the list.\\ \\  Note that is possible to use a different image for the currently selected item from that shown against the item in the drop-down list. If it's not convenient to define the text and image(s) at the same time, you can set the value of **cbxi.mask%** according to which you want to set.\\ \\  To test which item in the extended combobox is selected you can use exactly the same code as for a regular combobox:\\ \\  Here **itemno%** is the item to define (starting at zero for the first item), **imageno%** is the image to display alongside the text (zero for the first image in the image list) and **text$** is the text for this item. Note particularly the **CHR$0** termination for the text string. You can set **itemno%** to the special value **-1**, which adds it at the end of the list.\\ \\  Note that is possible to use a different image for the currently selected item from that shown against the item in the drop-down list. If it's not convenient to define the text and image(s) at the same time, you can set the value of **cbxi.mask%** according to which you want to set.\\ \\  To test which item in the extended combobox is selected you can use exactly the same code as for a regular combobox:\\ \\ 
 +<code bb4w>
         CB_GETCURSEL = &147         CB_GETCURSEL = &147
         SYS "SendDlgItemMessage", !dlg%, cbid%, CB_GETCURSEL, 0, 0 TO selected%         SYS "SendDlgItemMessage", !dlg%, cbid%, CB_GETCURSEL, 0, 0 TO selected%
 +</code>
 \\  \\ 
 ===== Main output window ===== ===== Main output window =====
 \\  The process for creating an extended combobox on the main output window is very similar to that for creating one in a dialogue box. As usual, we must install the appropriate library for working with boxes and buttons:\\ \\  \\  The process for creating an extended combobox on the main output window is very similar to that for creating one in a dialogue box. As usual, we must install the appropriate library for working with boxes and buttons:\\ \\ 
 +<code bb4w>
         INSTALL @lib$+"WINLIB5"         INSTALL @lib$+"WINLIB5"
 +</code>
 (alternatively install **WINLIB5A**, and remember to pass the parent window handle **@hwnd%** as the first parameter of **FN_createwindow**).\\ \\  The extended combobox is created as follows:\\ \\  (alternatively install **WINLIB5A**, and remember to pass the parent window handle **@hwnd%** as the first parameter of **FN_createwindow**).\\ \\  The extended combobox is created as follows:\\ \\ 
 +<code bb4w>
         WS_VSCROLL = &200000         WS_VSCROLL = &200000
         CBS_AUTOHSCROLL = &40         CBS_AUTOHSCROLL = &40
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         hcbex% = FN_createwindow("ComboBoxEx32", "", 200, 50, 140, 200, 0, \         hcbex% = FN_createwindow("ComboBoxEx32", "", 200, 50, 140, 200, 0, \
         \        WS_VSCROLL OR CBS_AUTOHSCROLL OR CBS_DROPDOWN, 0)         \        WS_VSCROLL OR CBS_AUTOHSCROLL OR CBS_DROPDOWN, 0)
 +</code>
 Refer to the documentation for [[http://www.bbcbasic.co.uk/bbcwin/manual/bbcwing.html#fnwindow|FN_createwindow]] for the meaning of the parameters. \\ \\  The next step is to tell the combobox which image list to use:\\ \\  Refer to the documentation for [[http://www.bbcbasic.co.uk/bbcwin/manual/bbcwing.html#fnwindow|FN_createwindow]] for the meaning of the parameters. \\ \\  The next step is to tell the combobox which image list to use:\\ \\ 
 +<code bb4w>
         CBEM_SETIMAGELIST = &402         CBEM_SETIMAGELIST = &402
         SYS "SendMessage", hcbex%, CBEM_SETIMAGELIST, 0, himglist%         SYS "SendMessage", hcbex%, CBEM_SETIMAGELIST, 0, himglist%
 +</code>
 Note the use of the combobox's window handle **hcbex%**.\\ \\  We declare some constants and a data structure exactly as before:\\ \\  Note the use of the combobox's window handle **hcbex%**.\\ \\  We declare some constants and a data structure exactly as before:\\ \\ 
 +<code bb4w>
         CBEIF_TEXT = 1         CBEIF_TEXT = 1
         CBEIF_IMAGE = 2         CBEIF_IMAGE = 2
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         DIM cbxi{mask%, iItem%, pszText%, cchTextMax%, iImage%, iSelectedImage%, \         DIM cbxi{mask%, iItem%, pszText%, cchTextMax%, iImage%, iSelectedImage%, \
         \        iOverlay%, iIndent%, lParam}         \        iOverlay%, iIndent%, lParam}
 +</code>
 Now we can define each item as follows:\\ \\  Now we can define each item as follows:\\ \\ 
 +<code bb4w>
           text$ = "Combobox item"+CHR$0           text$ = "Combobox item"+CHR$0
           cbxi.mask% = CBEIF_TEXT OR CBEIF_IMAGE OR CBEIF_SELECTEDIMAGE           cbxi.mask% = CBEIF_TEXT OR CBEIF_IMAGE OR CBEIF_SELECTEDIMAGE
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           cbxi.iSelectedImage% = imageno%           cbxi.iSelectedImage% = imageno%
           SYS "SendMessage", hcbex%, CBEM_INSERTITEMA, 0, cbxi{} TO res%           SYS "SendMessage", hcbex%, CBEM_INSERTITEMA, 0, cbxi{} TO res%
 +</code>
 Here **itemno%** is the item to define (starting at zero for the first item), **imageno%** is the image to display alongside the text (zero for the first image in the image list) and **text$** is the text for this item. Note particularly the **CHR$0** termination for the text string. You can set **itemno%** to the special value **-1**, which adds it at the end of the list.\\ \\  Note that is possible to use a different image for the currently selected item from that shown against the item in the drop-down list. If it's not convenient to define the text and image(s) at the same time, you can set the value of **cbxi.mask%** according to which you want to set.\\ \\  To test which item in the extended combobox is selected you can use exactly the same code as for a regular combobox:\\ \\  Here **itemno%** is the item to define (starting at zero for the first item), **imageno%** is the image to display alongside the text (zero for the first image in the image list) and **text$** is the text for this item. Note particularly the **CHR$0** termination for the text string. You can set **itemno%** to the special value **-1**, which adds it at the end of the list.\\ \\  Note that is possible to use a different image for the currently selected item from that shown against the item in the drop-down list. If it's not convenient to define the text and image(s) at the same time, you can set the value of **cbxi.mask%** according to which you want to set.\\ \\  To test which item in the extended combobox is selected you can use exactly the same code as for a regular combobox:\\ \\ 
 +<code bb4w>
         CB_GETCURSEL = &147         CB_GETCURSEL = &147
         SYS "SendMessage", hcbex%, CB_GETCURSEL, 0, 0 TO selected%         SYS "SendMessage", hcbex%, CB_GETCURSEL, 0, 0 TO selected%
 +</code>
the_20extended_20combobox.1522502386.txt.gz · Last modified: 2024/01/05 00:16 (external edit)