Merge pull request #138 from barun-saha/visual

helpers/pptx_helper.py

@@ -213,6 +213,10 @@ def generate_powerpoint_presentation(
 
         except Exception:
             # In case of any unforeseen error, try to salvage what is available
+            logger.error(
+                'An error occurred while processing a slide...continuing with the next one',
+                exc_info=True
+            )
             continue
 
     # The thank-you slide
@@ -356,7 +360,7 @@ def _handle_default_display(
 
 
 def _handle_display_image__in_foreground(
-        presentation: pptx.Presentation(),
+        presentation: pptx.Presentation,
         slide_json: dict,
         slide_width_inch: float,
         slide_height_inch: float
@@ -434,7 +438,7 @@ def _handle_display_image__in_foreground(
 
 
 def _handle_display_image__in_background(
-        presentation: pptx.Presentation(),
+        presentation: pptx.Presentation,
         slide_json: dict,
         slide_width_inch: float,
         slide_height_inch: float
@@ -465,7 +469,6 @@ def _handle_display_image__in_background(
         body_shape = slide.shapes.placeholders[placeholders[0][0]]
 
     title_shape.text = remove_slide_number_from_heading(slide_json['heading'])
-
     flat_items_list = get_flat_list_of_contents(slide_json['bullet_points'], level=0)
     add_bulleted_items(body_shape.text_frame, flat_items_list)
 
@@ -486,6 +489,39 @@ def _handle_display_image__in_background(
                 width=pptx.util.Inches(slide_width_inch),
             )
 
+            try:
+                # Find all blip elements to handle potential multiple instances
+                blip_elements = picture._element.xpath('.//a:blip')
+                if not blip_elements:
+                    logger.warning(
+                        'No blip element found in the picture. Transparency cannot be applied.'
+                    )
+                    return True
+
+                for blip in blip_elements:
+                    # Add transparency to the image through the blip properties
+                    alpha_mod = blip.makeelement(
+                        '{http://schemas.openxmlformats.org/drawingml/2006/main}alphaModFix'
+                    )
+                    # Opacity value between 0-100000
+                    alpha_mod.set('amt', '50000')  # 50% opacity
+
+                    # Check if alphaModFix already exists to avoid duplicates
+                    existing_alpha_mod = blip.find(
+                        '{http://schemas.openxmlformats.org/drawingml/2006/main}alphaModFix'
+                    )
+                    if existing_alpha_mod is not None:
+                        blip.remove(existing_alpha_mod)
+
+                    blip.append(alpha_mod)
+                    logger.debug('Added transparency to blip element: %s', blip.xml)
+
+            except Exception as ex:
+                logger.error(
+                    'Failed to apply transparency to the image: %s. Continuing without it.',
+                    str(ex)
+                )
+
             _add_text_at_bottom(
                 slide=slide,
                 slide_width_inch=slide_width_inch,
@@ -495,20 +531,29 @@ def _handle_display_image__in_background(
             )
 
             # Move picture to background
-            # https://github.com/scanny/python-pptx/issues/49#issuecomment-137172836
-            slide.shapes._spTree.remove(picture._element)
-            slide.shapes._spTree.insert(2, picture._element)
+            try:
+                slide.shapes._spTree.remove(picture._element)
+                slide.shapes._spTree.insert(2, picture._element)
+            except Exception as ex:
+                logger.error(
+                    'Failed to move image to background: %s. Image will remain in foreground.',
+                    str(ex)
+                )
+
+            return True
+
     except Exception as ex:
         logger.error(
-            '*** Error occurred while running adding image to the slide background: %s',
+            '*** Error occurred while adding image to the slide background: %s',
             str(ex)
         )
+        return True
 
     return True
 
 
 def _handle_icons_ideas(
-        presentation: pptx.Presentation(),
+        presentation: pptx.Presentation,
         slide_json: dict,
         slide_width_inch: float,
         slide_height_inch: float
@@ -656,7 +701,7 @@ def _add_text_at_bottom(
 
 
 def _handle_double_col_layout(
-        presentation: pptx.Presentation(),
+        presentation: pptx.Presentation,
         slide_json: dict,
         slide_width_inch: float,
         slide_height_inch: float