add QCodeEditor

external/QCodeEditor/README.md

@@ -0,0 +1,68 @@
+# Qt Code Editor Widget
+It's a widget for editing/viewing code.
+
+This project uses a resource named `qcodeeditor_resources.qrc`. The main application
+must not use a resource file with the same name.
+
+(It's not a project from a Qt example.)
+
+## Requirements
+0. C++11 featured compiler.
+0. Qt 5.
+
+## Abilities
+1. Auto parentheses.
+1. Different highlight rules.
+1. Auto indentation.
+1. Replace tabs with spaces.
+1. GLSL completion rules.
+1. GLSL highlight rules.
+1. C++ highlight rules.
+1. XML highlight rules.
+1. JSON highligh rules.
+1. Frame selection.
+1. Qt Creator styles.
+
+## Build
+It's a CMake-based library, so it can be used as a submodule (see the example).
+But here are the steps to build it as a static library (for external use for example).
+
+1. Clone the repository: `git clone https://github.com/Megaxela/QCodeEditor`
+1. Go into the repository: `cd QCodeEditor`
+1. Create a build folder: `mkdir build`
+1. Go into the build folder: `cd build`
+1. Generate a build file for your compiler: `cmake ..`
+    1. If you need to build the example, specify `-DBUILD_EXAMPLE=On` on this step.
+1. Build the library: `cmake --build .`
+
+## Example
+
+By default, `QCodeEditor` uses the standard QtCreator theme. But you may specify
+your own by parsing it with `QSyntaxStyle`. The example uses [Dracula](https://draculatheme.com) theme.
+(See the example for more.) 
+
+<img src="https://github.com/Megaxela/QCodeEditor/blob/master/example/image/preview.png">
+
+## LICENSE
+
+<img align="right" src="http://opensource.org/trademarks/opensource/OSI-Approved-License-100x137.png">
+
+Library is licensed under the [MIT License](https://opensource.org/licenses/MIT)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.