minui/minui.h

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _MINUI_H_
#define _MINUI_H_

#include <sys/types.h>

#include <stdbool.h>

#ifdef __cplusplus
extern "C" {
#endif

typedef struct {
    int width;
    int height;
    int row_bytes;
    int pixel_bytes;
    unsigned char* data;
} GRSurface;

typedef GRSurface* gr_surface;

int gr_init(void);
void gr_exit(void);

int gr_fb_width(void);
int gr_fb_height(void);

void gr_flip(void);
void gr_fb_blank(bool blank);

void gr_clear();  // clear entire surface to current color
void gr_color(unsigned char r, unsigned char g, unsigned char b, unsigned char a);
void gr_fill(int x1, int y1, int x2, int y2);
void gr_text(int x, int y, const char *s, int bold);
void gr_texticon(int x, int y, gr_surface icon);
int gr_measure(const char *s);
void gr_font_size(int *x, int *y);

void gr_blit(gr_surface source, int sx, int sy, int w, int h, int dx, int dy);
unsigned int gr_get_width(gr_surface surface);
unsigned int gr_get_height(gr_surface surface);

// input event structure, include <linux/input.h> for the definition.
// see http://www.mjmwired.net/kernel/Documentation/input/ for info.
struct input_event;

typedef int (*ev_callback)(int fd, short revents, void *data);
typedef int (*ev_set_key_callback)(int code, int value, void *data);

int ev_init(ev_callback input_cb, void *data);
void ev_exit(void);
int ev_add_fd(int fd, ev_callback cb, void *data);
int ev_sync_key_state(ev_set_key_callback set_key_cb, void *data);

/* timeout has the same semantics as for poll
 *    0 : don't block
 *  < 0 : block forever
 *  > 0 : block for 'timeout' milliseconds
 */
int ev_wait(int timeout);

int ev_get_input(int fd, short revents, struct input_event *ev);
void ev_dispatch(void);

// Resources

// res_create_*_surface() functions return 0 if no error, else
// negative.
//
// A "display" surface is one that is intended to be drawn to the
// screen with gr_blit().  An "alpha" surface is a grayscale image
// interpreted as an alpha mask used to render text in the current
// color (with gr_text() or gr_texticon()).
//
// All these functions load PNG images from "/res/images/${name}.png".

// Load a single display surface from a PNG image.
int res_create_display_surface(const char* name, gr_surface* pSurface);

// Load an array of display surfaces from a single PNG image.  The PNG
// should have a 'Frames' text chunk whose value is the number of
// frames this image represents.  The pixel data itself is interlaced
// by row.
int res_create_multi_display_surface(const char* name,
                                     int* frames, gr_surface** pSurface);

// Load a single alpha surface from a grayscale PNG image.
int res_create_alpha_surface(const char* name, gr_surface* pSurface);

// Load part of a grayscale PNG image that is the first match for the
// given locale.  The image is expected to be a composite of multiple
// translations of the same text, with special added rows that encode
// the subimages' size and intended locale in the pixel data.  See
// development/tools/recovery_l10n for an app that will generate these
// specialized images from Android resources.
int res_create_localized_alpha_surface(const char* name, const char* locale,
                                       gr_surface* pSurface);

// Free a surface allocated by any of the res_create_*_surface()
// functions.
void res_free_surface(gr_surface surface);

#ifdef __cplusplus
}
#endif

#endif