screen_photomode_save.c

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/**************************************************************************************************************************************
* Project:       discoverpixy
* Website:       https://github.com/t-moe/discoverpixy
* Authors:       Aaron Schmocker, Timo Lang
* Institution:   BFH Bern University of Applied Sciences
* File:          common/app/screen_photomode_save.c
*
* Version History:
* Date          Autor Email         SHA     Changes
* 2015-05-16    timolang@gmail.com  62006e0 Documented pixy_helper and implemented/finished photo-mode screens! Snap some shots!
* 2015-06-07    timolang@gmail.com  c87220d Renamed pixy_helper to pixy_frame. Updated docu of appliaction. added doxygen comments to pixy_{frame,control}.h
*
**************************************************************************************************************************************/

#include "screen_photomode_save.h"
#include "filesystem.h"
#include "button.h"
#include "tft.h"
#include "touch.h"
#include "pixy.h"
#include "pixy_frame.h"
#include <stdlib.h>
#include <string.h>


static BUTTON_STRUCT b_back; //Button to navigate back
static TOUCH_AREA_STRUCT a_area; //Touch area to select the save-file

//Callback for when the user presses the "back" button
static void b_back_cb(void* button)
{
    gui_screen_back();
}

static int num_files_ok; //number of files into which we can write the image (size, flags ok)
static enum {init, error, showlist, picking, saving, done} state; //Current state of the screen state machine
static int fontheight; //The space between one line of text to the next
static int liststart; //The y-Coordinate of the Start of the File-List
static const char* picked_file; //The filename picked by the user, to save the image to

//Linked list structure to save all files which are suitable for saving.
typedef struct FILE_LIST_ENTRY_S {
    char* filename; //Name of the file
    struct FILE_LIST_ENTRY_S* next; //Pointer to the next entry in the list or NULL
} FILE_LIST_ENTRY;

static FILE_LIST_ENTRY* files_ok; //Pointer to the head of the list

//Callback for when the user selects a file to save the image into
static void touchCB(void* touchArea, TOUCH_ACTION triggeredAction)
{

    int y = touch_get_last_point().y - liststart; //Calculate the y-Coordinate of the touch point relative to the start of the file-list
    int elem = y / fontheight; //Calculate the file index

    if (elem < 0 | elem >= num_files_ok) {
        return;    //Check if the file index is valid  (0,1,..,num_files_ok-1)
    }

    //Search for the corresponding entry in the linked list
    FILE_LIST_ENTRY* current_entry = files_ok; //Start walking through the list, starting by the head of the list

    for (int i = 0; i < elem; i++) { //Until we have reached the file (index)
        current_entry = current_entry->next; //traverse to the next file
    }

    picked_file = current_entry->filename; //save the picked filename. It will be used by the statemachine in the main loop
    touch_unregister_area(&a_area); //unregister the touch area, we no longer need it. No more interrupts will be fired.
    state = saving; //Change the state of the  statemachine
}

//Text-Lines to show if we have no matching files (num_files_ok==0)
static const char* nomatch_text [] = {
    "Due to limitations of the filesystem",
    "implementation you can only write to",
    "existing files.",
    "",
    "The files need to have a .bmp",
    "extension and must be at least",
    "189410 bytes (185kb) large.",
    "Unfortunately there were no such",
    "files found in the root directory.",
    "",
    "Please create some files and come",
    "back again.",
    NULL
};


//Bitmap header for a 318x198x24bit windows bitmap. data starts at 0x7A (= after this header)
//This header has been taken from a white bitmap saved with gimp.
//Wikipedia has a pretty good description on the header: http://de.wikipedia.org/wiki/Windows_Bitmap
static unsigned char bmpheader_data[0x7A] = {
    0x42, 0x4d, 0xe2, 0xe3, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7a, 0x00,
    0x00, 0x00, 0x6c, 0x00, 0x00, 0x00, 0x3e, 0x01, 0x00, 0x00, 0xc6, 0x00,
    0x00, 0x00, 0x01, 0x00, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x68, 0xe3,
    0x02, 0x00, 0x13, 0x0b, 0x00, 0x00, 0x13, 0x0b, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x42, 0x47, 0x52, 0x73, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00
};

//Callback for when the screen is entered/loaded
static void enter(void* screen)
{
    tft_clear(WHITE);


#define X_OFS 5

    //Back button
    b_back.base.x1 = X_OFS; //Start X of Button
    b_back.base.y1 = 210; //Start Y of Button
    b_back.base.x2 = AUTO; //Auto Calculate X2 with String Width
    b_back.base.y2 = AUTO; //Auto Calculate Y2 with String Height
    b_back.txtcolor = WHITE; //Set foreground color
    b_back.bgcolor = HEX(0xAE1010); //Set background color (Don't take 255 or 0 on at least one channel, to make shadows possible)
    b_back.font = 0; //Select Font
    b_back.text = "Back"; //Set Text (For formatted strings take sprintf)
    b_back.callback = b_back_cb; //Call b_back_cb as Callback
    gui_button_add(&b_back); //Register Button (and run the callback from now on)

    state = init; //Start with the init state
    fontheight = tft_font_height(0) + 2; //Save the height of the used font, for fast access
    files_ok = NULL; //initialize the linked list with 0 elements
    num_files_ok = 0; //we have zero! elements
}

//Callback for when the screen should be updated
//This is the main loop of the screen. This method will be called repeatedly
static void update(void* screen)
{
    switch (state) {
    case init: { //Init State: The user just entered the screen
        DIRECTORY_STRUCT* dir = filesystem_dir_open("."); //open root directory

        if (dir == NULL) { //error while opening root directory
            tft_print_line(X_OFS, 5, BLACK, TRANSPARENT, 0, "Error accessing Filesystem");
            state = error;
            break;
        }

        bool nomatch = true; //whether or not we have zero files which are suitable for saving

        for (int i = 0; i < dir->num_files; i++) { //walk through all files in the directory
            FILE_STRUCT* file = &(dir->files[i]); //Pointer to the current file/subdirectory

            //Ignore directories, archives, hidden files, system files and files we cannot write to
            if (file->fattrib & (F_SYS | F_HID | F_ARC | F_DIR | F_RDO)) {
                continue;
            }

            //ignore files which are not large enough
            if (file->fsize < 189410) {
                continue;    //size taken from an example bitmap (318x198x24)
            }

            nomatch = false; //at least one file matches
            break;
        }

        if (nomatch) { //not one file is suitable for writing
            int y = 5; //y-Coordinate where to start writing the error text
            int i = 0;

            while (nomatch_text[i] != NULL) { //for every line in the big error array
                //Write the line's text and go to the next line
                tft_print_line(X_OFS, y + i * fontheight, BLACK, TRANSPARENT, 0, nomatch_text[i]);
                i++;
            }

            state = error;
        } else { //we have a least one suitable file
            state = showlist;
        }

        filesystem_dir_close(dir); //free directory struct
    }
    break;

    case showlist: { //Show List State: Where we load and present the suitable file's to the user in a list
        DIRECTORY_STRUCT* dir2 = filesystem_dir_open("."); //Open the directory again

        if (dir2 == NULL) {
            return;    //Error on opening? This should never happen, since it's handled in the previous state
        }

        int y = 5; //y-Coordinate where to start drawing/writing text/list-elements

        tft_print_line(X_OFS, y, BLACK, TRANSPARENT, 0, "Pick a file to save the image to");
        y += fontheight + 5;

        tft_print_line(X_OFS, y, BLUE, TRANSPARENT, 0, "Name             Modified          Size");
        y += fontheight;

        liststart = y; //store the y coordinate of the start of the list away (used in toucharea callback)
        num_files_ok = 0; //we start with 0 matching files

        FILE_LIST_ENTRY* current_entry = NULL; //We start with an empty list

        for (int i = 0; i < dir2->num_files && num_files_ok < 10; i++) { //go through all the files of the directory, abort if we have 10 matches
            FILE_STRUCT* file = &(dir2->files[i]);

            //Ignore directories, archives, hidden files, system files and files we cannot write to
            if (file->fattrib & (F_SYS | F_HID | F_ARC | F_DIR | F_RDO)) {
                continue;
            }

            //ignore files which are not large enough
            if (file->fsize < 189410) {
                continue;    //size taken from an example bitmap (318x198x24)
            }

            //Print out filename, modified date,time and file size
            tft_print_formatted(X_OFS, y, BLACK,
                                TRANSPARENT, 0, "%-16s %02u.%02u.%02u %02u:%02u:%02u %u",
                                file->fname,
                                file->fdate.day,
                                file->fdate.month,
                                (file->fdate.year + 1980) % 100,
                                file->ftime.hour,
                                file->ftime.min,
                                file->ftime.sec * 2,
                                file->fsize);

            if (current_entry == NULL) { //The list is empty
                current_entry = malloc(sizeof(FILE_LIST_ENTRY)); //create new entry
                files_ok = current_entry; //assign it to the list head
            } else { //there's a least one entry in the list
                current_entry->next = malloc(sizeof(FILE_LIST_ENTRY)); //append entry to previous entry
                current_entry = current_entry->next; //newly created entry is the current now.
            }

            current_entry->next = NULL; //we're at the end of the list (for now)
            current_entry->filename = malloc(strlen(file->fname) + 1); //allocate space for the filename + zero-termination
            strcpy(current_entry->filename, file->fname); //copy filename (so that we can close the directory after scanning)

            //since we have found a suitable file we need to increment the position in the list
            num_files_ok++;
            y += fontheight;
        }

        //Touch area for file-selection (in the list)
        a_area.hookedActions = PEN_UP; //we're only interested in PEN_UP events
        a_area.x1 = X_OFS; //Left border
        a_area.y1 = liststart; //Start where the list started
        a_area.x2 = 320 - X_OFS; //Right border
        a_area.y2 = liststart + fontheight * num_files_ok; //stop at the end of the list
        a_area.callback = touchCB; //execute our callback when PEN_UP occurs
        touch_register_area(&a_area); //register the touch area and receive events from now on

        filesystem_dir_close(dir2); //we no longer need the directory struct, since we have our own linked list now

        state = picking;
    }
    break;

    case picking: //Picking State: Where we wait on the users file choice
        pixy_service(); //Handle pending pixy events
        //do nothing and wait on user to pick a file
        break;

    case saving: { //Saving State: Where we save the image to the selected file
        FILE_HANDLE* file = filesystem_file_open(picked_file); //try to open the selected file

        if (file == NULL) { //opening the file failed
            tft_print_formatted(X_OFS, 190, BLUE, TRANSPARENT, 0, "Could not open %s", picked_file);
            state = error;
            break;
        }

        filesystem_file_seek(file, 0); //seek to the start of the file (optional?)

        if (filesystem_file_write(file, bmpheader_data, 0x7A) != F_OK) { //Writing the header failed
            tft_print_formatted(X_OFS, 190, BLUE, TRANSPARENT, 0, "Error while writing to %s", picked_file);
            filesystem_file_close(file);
            state = error;
            break;
        }

        if (pixy_save_full_frame(file) != 0) { //Writing the imagedata failed
            tft_print_formatted(X_OFS, 190, BLUE, TRANSPARENT, 0, "Error while writing to %s", picked_file);
            filesystem_file_close(file);
            state = error;
            break;
        }

        //if we reach this point, we have written all data out successfully

        filesystem_file_close(file); //close/finalize the file
        tft_print_formatted(X_OFS, 190, BLUE, TRANSPARENT, 0, "Image saved to %s", picked_file);
        state = done;
    }
    break;

    case error: //Error State: Where we show an error message and leave the user no other choice than to click the backbutton
    case done: //Done State: When saving the file was successful
        pixy_service(); //Handle pending pixy events
        //wait on user to click the back button
        break;

    }
}

//Callback for when the screen is left/unloaded
static void leave(void* screen)
{
    gui_button_remove(&b_back); //Remove/Free the back button

    if (state == picking) { //The user left the screen in the "picking"-phase
        touch_unregister_area(&a_area); //remove the touch area (for the list)
    }

    if (state == picking || state == saving || state == done) { //the user left the screen after we created the linked list
        //Iterate through the linked list and free all resources
        FILE_LIST_ENTRY* current_entry = files_ok; //start with the list head

        while (current_entry != NULL) { //while we're not at the end
            FILE_LIST_ENTRY* temp = current_entry->next; //save the next pointer because we free the current element on the next line
            free((void*)(current_entry->filename)); //free filename
            free(current_entry); //free element itself
            current_entry = temp; //advance
        }
    }
}

//Declare screen callbacks
static SCREEN_STRUCT screen = {
    enter,
    leave,
    update
};

SCREEN_STRUCT* get_screen_photomodesave()
{
    return &screen;
}