Software Keyboard
The software keyboard (swkbd) expects to be passed three IStorages. See also AM_services#Library_Applets.
The below is for normal swkbd usage. There's also InlineKeyboard (added post-1.0.0), which doesn't run in the foreground and has completely different input/output IStorages. It also doesn't seem to display on the screen (or is optional at least): the user-process can get the gfx data via Display_services.
Library Applet Versions
| System Version | Value |
|---|---|
| 0x0..0x1 | |
| 0x2 | |
| 0x3..4 | |
| [1.0.0+] | 0x5 |
| [2.0.0+] | 0x10006 |
| [3.0.0+] | 0x30007 |
| [4.0.0+] | 0x40008 |
| [5.0.0+] | 0x50009 |
KeyboardConfig
The second IStorage passed to this applet should contain the configuration for the keyboard.
| Offset | Size | Typical Value | Notes |
|---|---|---|---|
| 0x0 | 4 | 2 | |
| 0x4 | 18 | 0 | UTF-16 text displayed in the submit button |
| 0x16 | 2 | 0 | UTF-16 "left optional symbol key" |
| 0x18 | 2 | 0 | UTF-16 "right optional symbol key" |
| 0x1A | 1 | 0 | Enables dictionary usage when non-zero (including the system dictionary). |
| 0x1C | 4 | 0 | Key set disable bitmask |
| 0x20 | 4 | 1 | Initial cursor position (0 = start of string, 1 = end of string) |
| 0x24 | 130 | u"" | UTF-16 header text |
| 0xA6 | 258 | u"" | UTF-16 sub text |
| 0x1A8 | 514 | u"" | UTF-16 guide text |
| 0x3AC | 4 | 0 | stringLenMax |
| 0x3B0 | 4 | 0 | stringLenMaxExt. When non-zero, specifies the max string length. When the input is too long, swkbd will display an icon and disable the ok-button. |
| 0x3B4 | 4 | 0 | Password flag (0 = not password, 1 = password) |
| 0x3B8 | 4 | 1 | |
| 0x3BC | 2 | 1 | Return button flag (0 = disable, non-zero = enable) |
| 0x3BE | 1 | 1 | Blur background (0 = no, 1 = yes) |
| 0x3C0 | 4 | 20 | Offset of initial string in work buffer (or 0) |
| 0x3C4 | 4 | 0 | Size of initial string in work buffer (bytes) |
| 0x3C8 | 4 | 2024 | Offset of user dictionary in work buffer (or 0) |
| 0x3CC | 4 | 0 | Length of user dictionary (number of entries) |
| 0x3D0 | 1 | 0 | #Text check enable |
| 0x3D8 | 8 | 0 | #Text check callback function address. Not sure why this is included here |
| 0x3E0 | 8 | -1 | |
| 0x3E8 | 8 | -1 | |
| 0x3F0 | 8 | -1 | |
| 0x3F8 | 8 | -1 |
This struct is 0x3E0-bytes with version 0x5. Starting with version 0x30007 this struct is 0x400-bytes.
The 0x20-bytes at offset 0x3E0 is -1 normally, except for DownloadCodes. This is presumably an extension to #Key Set Disable Bitmask?(The field at 0x1C is still set to 0x80 here)
If the length limit (stringLenMax) is <= 32, the text entry box will be a line and show the header/sub text. Otherwise, it will use a text-box and the header/sub text will not be shown. When the input is too long, swkbd will stop accepting more input until text is deleted via the B button (Backspace).
Each entry in the user dictionary is 100 bytes long.
Key Set Disable Bitmask
Various bits in this field disable certain keys on the keyboard. This list is incomplete.
0x02: disable ' ' 0x04: disable '@' 0x08: disable '%' 0x10: disable '\' and '/' 0x40: disable numbers 0x80: used for download codes
Work Buffer
This is the third IStorage passed to this applet. It is a transfer memory storage. The transfer memory should have size 0x1000 (0xd000 in certain cases) and permissions 0.
The layout of the work buffer doesn't seem to matter as long as the offsets in the #KeyboardConfig are adjusted, but official code lays it out like this.
Prior to version 0x5, offset 0x0 size 0x14(20) is a header (size 0x10 for version <=0x2).
| Offset | Size | Notes |
|---|---|---|
| 20 (decimal) | Unknown | UTF-16 initial string |
| 2024 (decimal) | Unknown | User dictionary |
Text Check
If text checking is enabled in #KeyboardConfig, text will be checked when the submit button is pressed. First, swkbd sends the text via PushInteractiveOutData. Normally size 0x7D4 is allocated for the string.
| Offset | Size | Notes |
|---|---|---|
| 0x0 | 0x8 | Buffer size |
| 0x8 | Variable | UTF-16 text |
The application then has an opportunity to validate or reject the text. It creates a new IStorage, writes the response to it, and sends it via PushInteractiveInData. This storage is 0x7D8-bytes.
| Offset | Size | Notes |
|---|---|---|
| 0x0 | 0x4 | TextCheckResult |
| 0x4 | Variable | UTF-16 error message (shown in a dialog box) |
TextCheckResult:
- 0: Success, valid string.
- 1: Failure, invalid string. Error message is displayed in a message-box, pressing OK will return to swkbd again.
- 2: Failure, invalid string. Error message is displayed in a message-box, pressing Cancel will return to swkbd again, while pressing OK will continue as if the text was valid.
- 3: Failure, invalid string. With value 3 and above, swkbd will silently not accept the string, without displaying any error.
Output
When either the submit button is pressed and input has been validated, or the user cancels the text entry, swkbd will push its response and exit. The response IStorage has the following format. This storage is 0x7D8-bytes.
| Offset | Size | Notes |
|---|---|---|
| 0x0 | 0x4 | Result code (0 = OK, 1 = Cancel) |
| 0x4 | Variable | UTF-16 text |