Cellwriter translucence and docking

Cellwriter is my primary on screen virtual keyboard now. But the docking or translucence does not work for me until recently. Now I finally find a way to make it work.

Translucence

Translucence is not the cellwriter's business in fact. It is done by a composite window manager such as compiz. To configure it in compiz, using compizconfig setting manager:

• Enable "Regex Matching" under "Utility" section.
• Enable "Opacity, Brightness and Saturation" under "Accessibility" section. Configure this item:
  • In "Opacity" tab page, add "Window specific settings", "class=Cellwriter" for "Windows", "50" for "Window values".

Docking

Cellwriter has full docking support in fact. But it does not work properly in metacity on x86_64. Seems there is a bug of cellwriter and an issue of metacity of gtk+.

• Enable "window docking" in cellwriter setup.
• Invoking cellwriter with command line option "—window-struts".
• Apply the patches to cellwriter (1.3.4).

At first, I found _NET_WM_STRUT_PARTIAL has no effect. After comparing the window strut setting of cellwriter and gnome-panel, I found the main difference lies in data type of struts structure passed into XChangeProperty. Cellwriter uses int, while gnome-panel uses gulong. So I try gulong in cellwriter, and it works like a charm!

Although the format of struts structure passed into XChangeProperty is 32, in "man XChangeProperty", I found following words:

"If the specified format is 32, the property data must be a long array."

So format 32 should be 64-bit on 64 bit machine in fact, and struts should be long instead of int.

Some software for tablet PC

• Stroke (gesture recognition)
  • I find easystroke is the best so far. To make it easier to enable/disable easytroke, (because several gesture recognition programs in system may conflict, for example, there is gesture recognition in firefox too.) I write a small patch to disable/enable easystroke with left button, which can be downloaded from here.
• Note taking with pen
  • I think xournal is very good. It can be used to add annotations to PDF files.

Firefox addons for tablet PC

• Grab and Drag

  Enables Adobe Acrobat-style grab and drag scrolling in Mozilla applications.

• All-in-One Gestures

  This extension allows you to execute common commands using mouse (pen) gestures.

  Several mouse gestures programs may conflict each other, so I write a simple AIOGControl (All-in-One Gestures) control addon to enable/disable All-in-One Gestures via a Firefox toolbar button. This is easier for pen to operate.

On screen keyboard

On screen keyboard is necessary for a tablet PC. Have tried several on screen keyboard implementation under X window, no one is perfect. Currently using one is cellwriter. Hope the one developed for Moblin will be better.

Requirement for on screen keyboard:

• Focus: the on screen keyboard should not be focused, and the faked key should be sent to the focused window.
• Window placement: the on screen keyboard window should not be covered by other windows (for example to be the top-most window), and it should not cover other windows completely (semi-transparent or docked at the desktop side, but it seems docking is not supported well in my metacity 2.24.0).
• Compatible with XIM. I am Chinese, I need use XIM to input Chinese.
• Configurable layout (to keep only the needed keys).
• Show/Hide can be controlled easily (via a panel button is preferable).
• Support screen rotation. On screen keyboard should not outside the screen or bigger than screen after rotation.
  

Tried on screen keyboard software:

• xvkbd: does not handle focus perfectly, the xvkbd itself seem be focused too (titlebar highlighted), so need two click for one key; need to specify which widget faked keys go, not very conveniently.
• matchbox-keyboard: good support for rotation, configurable laout, XIM, focus. Docking support for matchbox-wm is good. Original version does not support docking for metacity. I have a hack to support docking for metacity, but the hack doesn't support metacity 2.24.0. Show/Hide control can be done with daemon mode (-d) + matchbox-keyboard-toggler utility.
• gok (gnome on screen keyboard): recommended by many guys, but not good for me. Appears not works with XIM, and not works well without pointer in/out event.
• onboard: not used too much, I think it is good and simple.
  
• cellwriter: hand writing recoganizing program, but it is a good and simple on screen keyboard too. To use it as on screen keyboard add "--keyboard-only" to command line. Do no support configurable layout. Seems not support docking good.
  

Lenovo Thinkpad X61 Tablet

Bought a Lenovo Thinkpad X61 Tablet recently. Will post some usage tips. Most useful links:

http://www.thinkwiki.org/wiki/ThinkWiki