Icons: Add default icons (Use Apostolos E icons).

Minor formatting and use our own icons by Apostolos.
He already created the application icon. These look fine
with flat and dark theme.

AUTHORS

@@ -1,4 +1,4 @@
 Alastair Poole <netstar@gmail.com>
 
-Icon:
+Icons:
 Apostolos Bartziokas <barz621@gmail.com>

data/images/meson.build

@@ -0,0 +1,2 @@
+install_data('go-up.png', 'go-down.png',
+             install_dir: join_paths(dir_data, 'evisum/images'))

data/meson.build

@@ -1,2 +1,3 @@
 subdir('desktop')
 subdir('icons')
+subdir('images')

meson.build

@@ -26,6 +26,7 @@ dir_locale = join_paths(dir_prefix, get_option('localedir'))
 ##### config.h
 
 cfg.set_quoted('PACKAGE_VERSION', meson.project_version())
+cfg.set_quoted('PACKAGE_DATA_DIR', join_paths(dir_data, 'evisum'))
 configure_file(output: 'config.h', configuration: cfg)
 
 subdir('src')

src/bin/ui.c

@@ -1,3 +1,4 @@
+#include "config.h"
 #include "system.h"
 #include "process.h"
 #include "disks.h"
@@ -12,6 +13,7 @@
 
 static Eina_Lock _lock;
 
+
 void
 ui_shutdown(Ui *ui)
 {
@@ -110,6 +112,42 @@ _network_transfer_format(double rate)
    return strdup(eina_slstr_printf("%.2f %s", rate, unit));
 }
 
+char *
+_path_append(const char *path, const char *file)
+{
+   char *concat;
+   int len;
+   char separator = '/';
+#ifdef WIN32
+   separator = '\\';
+#endif
+
+   len = strlen(path) + strlen(file) + 2;
+   concat = malloc(len * sizeof(char));
+   snprintf(concat, len, "%s%c%s", path, separator, file);
+
+   return concat;
+}
+
+const char *
+_icon_path_get(const char *name)
+{
+   char *path;
+   const char *icon_path, *directory = PACKAGE_DATA_DIR "/images";
+   icon_path = name;
+
+   path = _path_append(directory, eina_slstr_printf("%s.png", name));
+   if (path)
+     {
+        if (ecore_file_exists(path))
+          icon_path = eina_slstr_printf("%s", path);
+
+        free(path);
+     }
+
+   return icon_path;
+}
+
 static void
 _tab_misc_update(Ui *ui, results_t *results)
 {
@@ -848,9 +886,9 @@ _btn_icon_state_set(Evas_Object *button, Eina_Bool reverse)
 {
    Evas_Object *icon = elm_icon_add(button);
    if (reverse)
-     elm_icon_standard_set(icon, "go-down");
+     elm_icon_standard_set(icon, _icon_path_get("go-down"));
    else
-     elm_icon_standard_set(icon, "go-up");
+     elm_icon_standard_set(icon, _icon_path_get("go-up"));
 
    elm_object_part_content_set(button, "icon", icon);
    evas_object_show(icon);