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Supporting and Using Extra Input Messages

How to support modern input devices and use the extra input messages in your MiniGUI apps.

Table of Contents

Overview

In MiniGUI 4.0.0, we introduce the extra input messages to support modern input devices including multiple touch panel, gesture, joystick, tablet tool, table pad, and even switch.

The extra input messages have the prefix MSG_EXIN_. If a MiniGUI app want to handle these extra input events such as gestures, you need to handle the MSG_EXIN_XXX messages in your window procedure.

Currently, there are two built-in IAL engines which can generates the extra input messages:

  • The IAL engine of libinput to support all modern input devices on a Linux box. This engine runs on libinput introduced by Free Desktop project.

  • The enhanced IAL engine of random to generate extra input messages automatically for testing.

You can also write your own IAL engines to generate the extra messages. Please see the implementation of libinput and random engines for the details.

This document describes how to handle the extra input messages and how to use libinput and random engines, or how to writing your own IAL engine to support a modern input devices, for example, a multi-touch panel.

Using the Extra Input Messages

Complie-time Configuration

Run-time Configuration

For libinput engine, we introduce a new section in MiniGUI runtime configuration:

[libinput]
seat=seat0

The key libinput.seat specifies the seat identifier, the default is seat0.

For random engine, we introduce a new section in MiniGUI runtime configuration:

[random]
logfile=events.out
eventtypes=mouse-keyboard-button-gesture-stouch
minkeycode=1
maxkeycode=128
minbtncode=0x100
maxbtncode=0x1ff

The MiniGUI runtime configuration key random.logfile specifies the log file which will store the input events generated by this engine. If MiniGUI failed to open the log file, the log feature will be disabled.

The MiniGUI runtime configuration key random.eventtypes specifies the input event types which will be generated by this IAL engine, in the following pattern:

<event-type>[-<event-type>]*

The <event-type> can be one of the following values:

  • mouse: mouse.
  • keyboard: keyboard.
  • button: buttons.
  • single_touch: touch pen or single touch panel.
  • multi_touch: multiple touch panel.
  • gesture: gesture.
  • tablet_tool: tablet tool.
  • tablet_pad: tablet pad.
  • switch: switch.

The MiniGUI ETC key random.minkeycode specifies the minimal key code which can be generated by the engine if keyboard is included.

The MiniGUI ETC key random.maxkeycode specifies the maximal key code which can be generated by the engine if keyboard is included.

The MiniGUI ETC key random.minbtncode specifies the minimal button code which can be generated by the engine if button is included.

The MiniGUI ETC key random.maxbtncode specifies the maximal key code which can be generated by the engine if button is included.

For invalid random.eventtyps, the engine uses mouse as default.

For invalid random.minkeycode, and/or random.maxkeycode key values, the engine uses SCANCODE_ESCAPE, and SCANCODE_MICMUTE respectively.

For invalid random.minbtncode, and/or random.maxbtncode key values, use 0x100 (BTN_MISC defined by Linux kernel), and 0x2ff (KEY_MAX defined by Linux kernel) respectively.

This engine maintains a state machine for each input event type, and generates a reasonable event sequence for each type. If and only if an event sequence finished or cancelled, the engine switch to another event type randomly.

Note that currently, the following event types (in random engine) are not implemented:

  • multi_touch
  • tablet_tool
  • tablet_pad
  • switch

Writing an IAL Engine to Support Extra Input Messages