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|
.. _architecture:
Architecture
============
TODO: this is a little outdated.
::
+---------------------------------------------------------------+
| InputStream |
| =========== |
| - Parses the input stream coming from a VT100 |
| compatible terminal. Translates it into data input |
| and control characters. Calls the corresponding |
| handlers of the `InputStreamHandler` instance. |
| |
| e.g. Translate '\x1b[6~' into "Keys.PageDown", call |
| the `feed_key` method of `InputProcessor`. |
+---------------------------------------------------------------+
|
v
+---------------------------------------------------------------+
| InputStreamHandler |
| ================== |
| - Has a `Registry` of key bindings, it calls the |
| bindings according to the received keys and the |
| input mode. |
| |
| We have Vi and Emacs bindings.
+---------------------------------------------------------------+
|
v
+---------------------------------------------------------------+
| Key bindings |
| ============ |
| - Every key binding consists of a function that |
| receives an `Event` and usually it operates on |
| the `Buffer` object. (It could insert data or |
| move the cursor for example.) |
+---------------------------------------------------------------+
|
| Most of the key bindings operate on a `Buffer` object, but
| they don't have to. They could also change the visibility
| of a menu for instance, or change the color scheme.
|
v
+---------------------------------------------------------------+
| Buffer |
| ====== |
| - Contains a data structure to hold the current |
| input (text and cursor position). This class |
| implements all text manipulations and cursor |
| movements (Like e.g. cursor_forward, insert_char |
| or delete_word.) |
| |
| +-----------------------------------------------+ |
| | Document (text, cursor_position) | |
| | ================================ | |
| | Accessed as the `document` property of the | |
| | `Buffer` class. This is a wrapper around the | |
| | text and cursor position, and contains | |
| | methods for querying this data , e.g. to give | |
| | the text before the cursor. | |
| +-----------------------------------------------+ |
+---------------------------------------------------------------+
|
| Normally after every key press, the output will be
| rendered again. This happens in the event loop of
| the `Application` where `Renderer.render` is called.
v
+---------------------------------------------------------------+
| Layout |
| ====== |
| - When the renderer should redraw, the renderer |
| asks the layout what the output should look like. |
| - The layout operates on a `Screen` object that he |
| received from the `Renderer` and will put the |
| toolbars, menus, highlighted content and prompt |
| in place. |
| |
| +-----------------------------------------------+ |
| | Menus, toolbars, prompt | |
| | ======================= | |
| | | |
| +-----------------------------------------------+ |
+---------------------------------------------------------------+
|
v
+---------------------------------------------------------------+
| Renderer |
| ======== |
| - Calculates the difference between the last output |
| and the new one and writes it to the terminal |
| output. |
+---------------------------------------------------------------+
|
