Allow reading more image formats as covers (All images will be converted to JPEG when stored). Fixes #1619993 [Request: Support for dragging TIFF files into Cover area](https://bugs.launchpad.net/calibre/+bug/1619993)

src/calibre/gui2/__init__.py

@@ -750,9 +750,11 @@ else:
                 ans = ans[0]
         return ans
 
-    def choose_images(window, name, title, select_only_single_file=True,
+    def choose_images(window, name, title, select_only_single_file=True, formats=None):
-                    formats=('png', 'gif', 'jpg', 'jpeg', 'svg')):
         mode = QFileDialog.ExistingFile if select_only_single_file else QFileDialog.ExistingFiles
+        if formats is None:
+            from calibre.gui2.dnd import image_extensions
+            formats = image_extensions()
         fd = FileDialog(title=title, name=name,
                         filters=[(_('Images'), list(formats))],
                         parent=window, add_all_files_filter=False, mode=mode,

src/calibre/gui2/actions/add.py

@@ -17,7 +17,6 @@ from calibre.gui2 import (error_dialog, choose_files, choose_dir,
 from calibre.gui2.dialogs.add_empty_book import AddEmptyBookDialog
 from calibre.gui2.dialogs.confirm_delete import confirm
 from calibre.gui2.dialogs.progress import ProgressDialog
-from calibre.gui2.widgets import IMAGE_EXTENSIONS
 from calibre.ebooks import BOOK_EXTENSIONS
 from calibre.utils.filenames import ascii_filename
 from calibre.utils.icu import sort_key
@@ -359,11 +358,12 @@ class AddAction(InterfaceAction):
                 return
             cid = db.id(current_idx.row()) if cid is None else cid
         formats = []
+        from calibre.gui2.dnd import image_extensions
         for path in paths:
             ext = os.path.splitext(path)[1].lower()
             if ext:
                 ext = ext[1:]
-            if ext in IMAGE_EXTENSIONS:
+            if ext in image_extensions():
                 pmap = QPixmap()
                 pmap.load(path)
                 if not pmap.isNull():

src/calibre/gui2/book_details.py

@@ -17,7 +17,7 @@ from PyQt5.QtWebKitWidgets import QWebView
 
 from calibre import fit_image
 from calibre.gui2.dnd import (dnd_has_image, dnd_get_image, dnd_get_files,
-    IMAGE_EXTENSIONS, dnd_has_extension)
+    dnd_has_extension, image_extensions)
 from calibre.ebooks import BOOK_EXTENSIONS
 from calibre.ebooks.metadata.book.base import (field_metadata, Metadata)
 from calibre.ebooks.metadata.book.render import mi_to_html
@@ -639,11 +639,10 @@ class BookDetails(QWidget):  # {{{
     open_fmt_with = pyqtSignal(int, object, object)
 
     # Drag 'n drop {{{
-    DROPABBLE_EXTENSIONS = IMAGE_EXTENSIONS+BOOK_EXTENSIONS
 
     def dragEnterEvent(self, event):
         md = event.mimeData()
-        if dnd_has_extension(md, self.DROPABBLE_EXTENSIONS, allow_all_extensions=True) or \
+        if dnd_has_extension(md, image_extensions() + BOOK_EXTENSIONS, allow_all_extensions=True) or \
                 dnd_has_image(md):
             event.acceptProposedAction()
 

src/calibre/gui2/dnd.py

@@ -13,7 +13,7 @@ from threading import Thread
 from Queue import Queue, Empty
 
 from PyQt5.Qt import QPixmap, Qt, QDialog, QLabel, QVBoxLayout, \
-        QDialogButtonBox, QProgressBar, QTimer, QUrl
+        QDialogButtonBox, QProgressBar, QTimer, QUrl, QImageReader
 
 from calibre.constants import DEBUG, iswindows
 from calibre.ptempfile import PersistentTemporaryFile
@@ -21,6 +21,12 @@ from calibre import browser, as_unicode, prints
 from calibre.gui2 import error_dialog
 from calibre.utils.imghdr import what
 
+def image_extensions():
+    if not hasattr(image_extensions, 'ans'):
+        image_extensions.ans = [bytes(x).decode('utf-8') for x in QImageReader.supportedImageFormats()]
+    return image_extensions.ans
+
+# This is present for compatibility with old plugins, do not use
 IMAGE_EXTENSIONS = ['jpg', 'jpeg', 'gif', 'png', 'bmp']
 
 class Worker(Thread):  # {{{
@@ -121,7 +127,7 @@ class DownloadDialog(QDialog):  # {{{
 
 def dnd_has_image(md):
     # Chromium puts image data into application/octet-stream
-    return md.hasImage() or md.hasFormat('application/octet-stream') and what(None, bytes(md.data('application/octet-stream'))) in IMAGE_EXTENSIONS
+    return md.hasImage() or md.hasFormat('application/octet-stream') and what(None, bytes(md.data('application/octet-stream'))) in image_extensions()
 
 def data_as_string(f, md):
     raw = bytes(md.data(f))
@@ -181,13 +187,12 @@ def dnd_has_extension(md, extensions, allow_all_extensions=False):
         return bool(exts)
     return bool(exts.intersection(frozenset(extensions)))
 
-def dnd_get_image(md, image_exts=IMAGE_EXTENSIONS):
+def dnd_get_image(md, image_exts=None):
     '''
     Get the image in the QMimeData object md.
 
     :return: None, None if no image is found
-             QPixmap, None if an image is found, the pixmap is guaranteed not
+             QPixmap, None if an image is found, the pixmap is guaranteed not null
-             null
              url, filename if a URL that points to an image is found
     '''
     if md.hasImage():
@@ -207,6 +212,9 @@ def dnd_get_image(md, image_exts=IMAGE_EXTENSIONS):
         if not pmap.isNull():
             return pmap, None
 
+    if image_exts is None:
+        image_exts = image_extensions()
+
     # No image, look for an URL pointing to an image
     urls = urls_from_md(md)
     paths = [path_from_qurl(u) for u in urls]

src/calibre/gui2/metadata/basic_widgets.py

@@ -1071,8 +1071,7 @@ class Cover(ImageView):  # {{{
 
     def select_cover(self, *args):
         files = choose_images(
-            self, 'change cover dialog', _('Choose cover for ') + self.dialog.title.current_val,
+            self, 'change cover dialog', _('Choose cover for ') + self.dialog.title.current_val)
-            formats=('png', 'gif', 'jpg', 'jpeg'))
         if not files:
             return
         _file = files[0]

src/calibre/gui2/tweak_book/editor/canvas.py

@@ -18,7 +18,7 @@ from PyQt5.Qt import (
 from calibre import fit_image
 from calibre.gui2 import error_dialog, pixmap_to_data
 from calibre.gui2.dnd import (
-    IMAGE_EXTENSIONS, dnd_has_extension, dnd_has_image, dnd_get_image, DownloadDialog)
+    image_extensions, dnd_has_extension, dnd_has_image, dnd_get_image, DownloadDialog)
 from calibre.gui2.tweak_book import capitalize
 from calibre.utils.imghdr import identify
 from calibre.utils.img import (
@@ -224,11 +224,10 @@ class Canvas(QWidget):
         return self.current_image is not self.original_image
 
     # Drag 'n drop {{{
-    DROPABBLE_EXTENSIONS = IMAGE_EXTENSIONS
 
     def dragEnterEvent(self, event):
         md = event.mimeData()
-        if dnd_has_extension(md, self.DROPABBLE_EXTENSIONS) or dnd_has_image(md):
+        if dnd_has_extension(md, image_extensions()) or dnd_has_image(md):
             event.acceptProposedAction()
 
     def dropEvent(self, event):

src/calibre/gui2/widgets.py

@@ -20,7 +20,7 @@ from calibre.ebooks import BOOK_EXTENSIONS
 from calibre.utils.config import prefs, XMLConfig
 from calibre.gui2.progress_indicator import ProgressIndicator as _ProgressIndicator
 from calibre.gui2.dnd import (dnd_has_image, dnd_get_image, dnd_get_files,
-    IMAGE_EXTENSIONS, dnd_has_extension, DownloadDialog)
+    image_extensions, dnd_has_extension, DownloadDialog)
 from calibre.utils.localization import localize_user_manual_link
 
 history = XMLConfig('history')
@@ -215,14 +215,15 @@ class ImageDropMixin(object):  # {{{
     Adds support for dropping images onto widgets and a context menu for
     copy/pasting images.
     '''
-    DROPABBLE_EXTENSIONS = IMAGE_EXTENSIONS
+    DROPABBLE_EXTENSIONS = None
 
     def __init__(self):
         self.setAcceptDrops(True)
 
     def dragEnterEvent(self, event):
         md = event.mimeData()
-        if dnd_has_extension(md, self.DROPABBLE_EXTENSIONS) or \
+        exts = self.DROPABBLE_EXTENSIONS or image_extensions()
+        if dnd_has_extension(md, exts) or \
                 dnd_has_image(md):
             event.acceptProposedAction()
 

src/calibre/gui2/win_file_dialogs.py

@@ -225,8 +225,10 @@ def choose_files(window, name, title,
         return ans
     return None
 
-def choose_images(window, name, title, select_only_single_file=True,
+def choose_images(window, name, title, select_only_single_file=True, formats=None):
-                  formats=('png', 'gif', 'jpg', 'jpeg', 'svg')):
+    if formats is None:
+        from calibre.gui2.dnd import image_extensions
+        formats = image_extensions()
     file_types = [(_('Images'), list(formats))]
     return choose_files(window, name, title, select_only_single_file=select_only_single_file, filters=file_types)