pax_keyboard.h

/*
	MIT License

	Copyright (c) 2022 Julian Scheffers

	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.
*/

#ifndef PAX_KEYBOARD_H
#define PAX_KEYBOARD_H

#include <pax_gfx.h>
#include <pax_shapes.h>
#include <pax_fonts.h>

// A number of inputs supported by the PAX keyboard.
typedef enum {
	// Represents no input being pressed.
	PKB_NO_INPUT,
	// Movement of the cursor.
	PKB_UP, PKB_DOWN, PKB_LEFT, PKB_RIGHT,
	// Delete to the left or the selection. Backspace key.
	PKB_DELETE_BEFORE,
	// Delete to the right or the selection. Delete key.
	PKB_DELETE_AFTER,
	// Switch between lower case, upper case and symbols.
	PKB_MODESELECT,
	// Enter a character.
	PKB_CHARSELECT,  
	// The same thing as the shift key.
	// Goes between PKB_LOWERCASE and PKB_UPPERCASE or PKB_NUMBERS and PKB_SYMBOLS.
	PKB_SHIFT,
} pkb_input_t;

// The type of keyboard currently selected.
typedef enum {
	// Lowercase and .,
	PKB_LOWERCASE,
	// Uppercase and <>
	PBK_UPPERCASE,
	// Numbers and symbols 1/2
	PKB_NUMBERS,
	// Symbols 2/2
	PKB_SYMBOLS,
} pkb_keyboard_t;

// The PAX keyboard context used for drawing and alike.
typedef struct {
	// Position on screen of the keyboard.
	int            x, y;
	// Maximum size of the keyboard.
	int            width, height;
	
	// Content of the keyboard.
	char          *content;
	// Size in bytes of capacity of the content buffer.
	size_t         content_cap;
	
	// Starting position of the selection in the text box.
	int            selection;
	// Cursor position of the text box.
	int            cursor;
	
	// Cursor position of the keyboard.
	int            key_x, key_y;
	// The currently held input.
	pkb_input_t    held;
	// The time that holding the input started.
	int64_t        hold_start;
	// The last time pkb_press was called.
	int64_t        last_press;
	
	// Whether the keyboard is multi-line.
	bool           multiline;
	// Whether the keyboard is in insert mode.
	bool           insert;
	// The board that is currently selected.
	pkb_keyboard_t board_sel;
	
	// The font to use for the keyboard.
	const pax_font_t *kb_font;
	// The font size to use for the keyboard.
	float          kb_font_size;
	// The font to use for the text.
	const pax_font_t *text_font;
	// The font size to use for the text.
	float          text_font_size;
	// The text color to use.
	pax_col_t      text_col;
	// The text color to use when a character is being held down.
	pax_col_t      sel_text_col;
	// The selection color to use.
	pax_col_t      sel_col;
	// The background color to use.
	pax_col_t      bg_col;
	
	// Whether something has changed since last draw.
	bool           dirty;
	// Whether the text has changed since last draw.
	bool           text_dirty;
	// Whether the keyboard has changed since last draw.
	bool           kb_dirty;
	// Whether just the selected character has changed since last draw.
	bool           sel_dirty;
	// Previous cursor position of the keyboard.
	// Used for sel_dirty.
	int            last_key_x, last_key_y;
	
	// Indicates that the input has been accepted.
	bool           input_accepted;
} pkb_ctx_t;

// Initialise the context with default settings.
void pkb_init   (pax_buf_t *buf, pkb_ctx_t *ctx, size_t buffer_cap);
// Free any memory associated with the context.
void pkb_destroy(pkb_ctx_t *ctx);
// Replaces the text in the keyboard with the given text.
// Makes a copy of the given text.
void pkb_set_content(pkb_ctx_t *ctx, const char *content);

// Redraw the complete on-screen keyboard.
void pkb_render (pax_buf_t *buf, pkb_ctx_t *ctx);
// Redraw only the changed parts of the on-screen keyboard.
void pkb_redraw (pax_buf_t *buf, pkb_ctx_t *ctx);

// The loop that allows input repeating.
void pkb_loop   (pkb_ctx_t *ctx);

// A pressing of the input.
void pkb_press  (pkb_ctx_t *ctx, pkb_input_t input);
// A relealing of the input.
void pkb_release(pkb_ctx_t *ctx, pkb_input_t input);

#endif //PAX_KEYBOARD_H