Initial png file parsing.

.indent.pro

@@ -65,6 +65,7 @@
 -T lxw_hash_table
 -T lxw_header_footer_options
 -T lxw_heading_pair
+-T lxw_image_meta
 -T lxw_image_options
 -T lxw_merged_range
 -T lxw_packager

include/xlsxwriter/common.h

@@ -19,16 +19,15 @@
 #define STATIC
 #endif
 
-#define LXW_SHEETNAME_MAX  32
-#define LXW_SHEETNAME_LEN  65
-#define LXW_UINT32_T_LEN   11   /* Length of 4294967296. */
-
 enum lxw_boolean {
     LXW_FALSE,
     LXW_TRUE
 };
 
-#define LXW_IGNORE 1
+#define LXW_SHEETNAME_MAX  32
+#define LXW_SHEETNAME_LEN  65
+#define LXW_UINT32_T_LEN   11   /* Length of 4294967296\0. */
+#define LXW_IGNORE          1
 
 #define LXW_ERROR(message)                      \
     fprintf(stderr, "[ERROR][%s:%d]: " message "\n", __FILE__, __LINE__)
@@ -55,10 +54,19 @@ enum lxw_boolean {
     }
 
 #define LXW_WARN(message)                       \
-    fprintf(stderr, "[WARN] %s(): " message "\n", __func__)
+    fprintf(stderr, "[WARN]: " message "\n")
 
 #define LXW_WARN_FORMAT(message, var)           \
-    fprintf(stderr, "[WARN] %s(): " message "\n", __func__, var)
+    fprintf(stderr, "[WARN]: " message "\n", var)
+
+#ifndef LXW_BIG_ENDIAN
+#define LXW_UINT32_NETWORK(n) ((((n) & 0xFF)       << 24) | \
+                               (((n) & 0xFF00)     <<  8) | \
+                               (((n) & 0xFF0000)   >>  8) | \
+                               (((n) & 0xFF000000) >> 24))
+#else
+#define LXW_UINT32_NETWORK(n) (n)
+#endif
 
 /* Compilers that have a native snprintf() can use it directly. */
 #ifdef _MSC_VER

include/xlsxwriter/workbook.h

@@ -44,6 +44,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <errno.h>
+#include <libgen.h>
 
 #include "worksheet.h"
 #include "shared_strings.h"
@@ -192,6 +193,7 @@ typedef struct lxw_workbook {
     uint16_t active_sheet;
     uint16_t num_xf_formats;
     uint16_t num_format_count;
+    uint16_t drawing_count;
 
     uint16_t font_count;
     uint16_t border_count;

include/xlsxwriter/worksheet.h

@@ -137,6 +137,13 @@ enum pane_types {
     FREEZE_SPLIT_PANES
 };
 
+enum image_types {
+    IMAGE_UNKNOWN = 0,
+    IMAGE_PNG,
+    IMAGE_JPG,
+    IMAGE_BMP
+};
+
 /* Define the tree.h RB structs for the red-black head types. */
 RB_HEAD(lxw_table_cells, lxw_cell);
 
@@ -271,6 +278,15 @@ typedef struct lxw_image_options {
     char *tip;
     uint8_t anchor;
 
+    /* Internal metadata. */
+    FILE *stream;
+    uint8_t image_type;
+    uint32_t width;
+    uint32_t height;
+    char *short_name;
+    double x_dpi;
+    double y_dpi;
+
     STAILQ_ENTRY (lxw_image_options) list_pointers;
 
 } lxw_image_options;

src/workbook.c

@@ -538,6 +538,171 @@ mem_error:
     return 1;
 }
 
+/*
+ * Extract width and height information from a PNG file.
+ */
+STATIC int
+_process_png(lxw_image_options *image_options)
+{
+    uint32_t length;
+    uint32_t offset;
+    char type[4];
+    uint32_t width = 0;
+    uint32_t height = 0;
+    double x_dpi = 96;
+    double y_dpi = 96;
+
+    FILE *stream = image_options->stream;
+
+    /* Skip another 4 bytes to the end of the PNG header. */
+    fseek(stream, 4, SEEK_CUR);
+
+    while (!feof(stream)) {
+
+        /* Read the PNG length and type fields for the sub-section. */
+        if (fread(&length, sizeof(length), 1, stream) < 1)
+            break;
+
+        if (fread(&type, 1, 4, stream) < 4)
+            break;
+
+        /* Convert the length to network order. */
+        length = LXW_UINT32_NETWORK(length);
+
+        /* The offset for next fseek() is the field length + type length. */
+        offset = length + 4;
+
+        if (memcmp(type, "IHDR", 4) == 0) {
+            if (fread(&width, sizeof(width), 1, stream) < 1)
+                break;
+
+            if (fread(&height, sizeof(height), 1, stream) < 1)
+                break;
+
+            width = LXW_UINT32_NETWORK(width);
+            height = LXW_UINT32_NETWORK(height);
+
+            /* Reduce the offset by the length of previous freads(). */
+            offset -= 8;
+        }
+
+        if (memcmp(type, "pHYs", 4) == 0) {
+            uint32_t x_ppu = 0;
+            uint32_t y_ppu = 0;
+            uint8_t units = 1;
+
+            if (fread(&x_ppu, sizeof(x_ppu), 1, stream) < 1)
+                break;
+
+            if (fread(&y_ppu, sizeof(y_ppu), 1, stream) < 1)
+                break;
+
+            if (fread(&units, sizeof(units), 1, stream) < 1)
+                break;
+
+            if (units == 1) {
+                x_dpi = (double) x_ppu *0.0254;
+                y_dpi = (double) y_ppu *0.0254;
+            }
+
+            /* Reduce the offset by the length of previous freads(). */
+            offset -= 9;
+        }
+
+        if (memcmp(type, "IEND", 4) == 0)
+            break;
+
+        if (!feof(stream))
+            fseek(stream, offset, SEEK_CUR);
+    }
+
+    /* Ensure that we read some valid data from the file. */
+    if (width == 0) {
+        LXW_WARN_FORMAT("worksheet_insert_image()/_opts(): "
+                        "no size data found in file: %s\n",
+                        image_options->filename);
+        return -1;
+    }
+
+    /* Set the image metadata. */
+    image_options->image_type = IMAGE_PNG;
+    image_options->width = width;
+    image_options->height = height;
+    image_options->x_dpi = x_dpi;
+    image_options->y_dpi = y_dpi;
+
+    return 0;
+}
+
+/*
+ * Extract information from the image file such as dimension, type, filename,
+ * and extension.
+ */
+STATIC int
+_get_image_properties(lxw_image_options *image_options)
+{
+    char *short_name;
+    char signature[4];
+
+    /* Read 4 bytes to look for the file header/signature. */
+    if (fread(signature, 1, 4, image_options->stream) < 4)
+        return -1;
+
+    if (memcmp(&signature[1], "PNG", 3) == 0) {
+        _process_png(image_options);
+    }
+    else {
+        LXW_WARN_FORMAT("worksheet_insert_image()/_opts(): "
+                        "unsupported image format for file: %s\n",
+                        image_options->filename);
+        return -1;
+    }
+
+    /* Get the filename from the full path to add to the Drawing object. */
+    short_name = basename(image_options->filename);
+    if (short_name)
+        image_options->short_name = lxw_strdup(short_name);
+    else
+        return -1;
+
+    return 0;
+}
+
+/*
+ * Iterate through the worksheets and set up any chart or image drawings.
+ */
+STATIC void
+_prepare_drawings(lxw_workbook *self)
+{
+    lxw_worksheet *worksheet;
+    lxw_image_options *image_options;
+    uint16_t image_ref_id = 0;
+    uint16_t drawing_id = 0;
+
+    STAILQ_FOREACH(worksheet, self->worksheets, list_pointers) {
+
+        if (STAILQ_EMPTY(worksheet->images))
+            continue;
+
+        drawing_id++;
+
+        STAILQ_FOREACH(image_options, worksheet->images, list_pointers) {
+
+            if (_get_image_properties(image_options) != 0)
+                continue;
+
+            image_ref_id++;
+
+            /*sheet->_prepare_image(index, image_ref_id, drawing_id, width,
+               height, name, type);
+             */
+        }
+
+    }
+
+    self->drawing_count = drawing_id;
+}
+
 /*
  * Iterate through the worksheets and store any defined names used for print
  * ranges or repeat rows/columns.
@@ -1117,6 +1282,9 @@ workbook_close(lxw_workbook *self)
     /* Set the defined names for the worksheets such as Print Titles. */
     _prepare_defined_names(self);
 
+    /* Prepare the drawings, charts and images. */
+    _prepare_drawings(self);
+
     /* Create a packager object to assemble sub-elements into a zip file. */
     packager = _new_packager(self->filename);
 

src/worksheet.c

@@ -206,6 +206,7 @@ _free_image_options(lxw_image_options *image)
         return;
 
     free(image->filename);
+    free(image->short_name);
     free(image->url);
     free(image->tip);
     free(image);
@@ -3718,7 +3719,8 @@ worksheet_set_zoom(lxw_worksheet *self, uint16_t scale)
 {
     /* Confine the scale to Excel"s range */
     if (scale < 10 || scale > 400) {
-        LXW_WARN("Zoom factor scale outside range: 10 <= zoom <= 400");
+        LXW_WARN("worksheet_set_zoom(): "
+                 "Zoom factor scale outside range: 10 <= zoom <= 400");
         return;
     }
 
@@ -3807,24 +3809,23 @@ worksheet_insert_image_opt(lxw_worksheet *self,
                            const char *filename,
                            lxw_image_options *user_options)
 {
-    FILE *file;
+    FILE *image_stream;
     lxw_image_options *options;
 
     if (!filename) {
-        LXW_WARN("filename must be specified");
+        LXW_WARN("worksheet_insert_image()/_opts(): "
+                 "filename must be specified");
         return -1;
     }
 
     /* Check that the image file exists and can be opened. */
-    file = fopen(filename, "rb");
-    if (!file) {
-        LXW_WARN_FORMAT("file doesn't exist or can't be opened: %s",
+    image_stream = fopen(filename, "rb");
+    if (!image_stream) {
+        LXW_WARN_FORMAT("worksheet_insert_image()/_opts(): "
+                        "file doesn't exist or can't be opened: %s",
                         filename);
         return -1;
     }
-    else {
-        fclose(file);
-    }
 
     /* Create a new object to hold the image options. */
     options = calloc(1, sizeof(lxw_image_options));
@@ -3838,6 +3839,7 @@ worksheet_insert_image_opt(lxw_worksheet *self,
 
     /* Copy other options or set defaults. */
     options->filename = lxw_strdup(filename);
+    options->stream = image_stream;
 
     if (!options->x_scale)
         options->x_scale = 1;
@@ -3861,23 +3863,5 @@ worksheet_insert_image(lxw_worksheet *self,
                        lxw_row_t row_num, lxw_col_t col_num,
                        const char *filename)
 {
-    FILE *file;
-
-    if (!filename) {
-        LXW_WARN("filename must be specified");
-        return -1;
-    }
-
-    /* Check that the image file exists and can be opened. */
-    file = fopen(filename, "rb");
-    if (!file) {
-        LXW_WARN_FORMAT("file doesn't exist or can't be opened: %s",
-                        filename);
-        return -1;
-    }
-    else {
-        fclose(file);
-    }
-
     return worksheet_insert_image_opt(self, row_num, col_num, filename, NULL);
 }