Api for changing sizes dynamically

pyWebLayout/layout/document_layouter.py

@@ -74,7 +74,16 @@ def paragraph_layouter(paragraph: Paragraph, page: Page, start_word: int = 0, pr
             int(concrete_style.word_spacing_max)
         )
         text_align = concrete_style.text_align
-    
+
+    # Apply page-level word spacing override if specified
+    if hasattr(page.style, 'word_spacing') and isinstance(page.style.word_spacing, int) and page.style.word_spacing > 0:
+        # Add the page-level word spacing to both min and max constraints
+        min_ws, max_ws = word_spacing_constraints
+        word_spacing_constraints = (
+            min_ws + page.style.word_spacing,
+            max_ws + page.style.word_spacing
+        )
+
     # Apply alignment override if provided
     if alignment_override is not None:
         text_align = alignment_override
@@ -91,9 +100,14 @@ def paragraph_layouter(paragraph: Paragraph, page: Page, start_word: int = 0, pr
             background=font.background
         )
     
-    # Calculate baseline-to-baseline spacing using line spacing multiplier
+    # Calculate baseline-to-baseline spacing: font size + additional line spacing
     # This is the vertical distance between baselines of consecutive lines
-    baseline_spacing = int(font.font_size * page.style.line_spacing_multiplier)
+    # Formula: baseline_spacing = font_size + line_spacing (absolute pixels)
+    line_spacing_value = getattr(page.style, 'line_spacing', 5)
+    # Ensure line_spacing is an int (could be Mock in tests)
+    if not isinstance(line_spacing_value, int):
+        line_spacing_value = 5
+    baseline_spacing = font.font_size + line_spacing_value
     
     # Get font metrics for boundary checking
     ascent, descent = font.font.getmetrics()

pyWebLayout/layout/ereader_layout.py

@@ -247,11 +247,16 @@ class BidirectionalLayouter:
             
             # Try to fit the block on the current page
             success, new_pos = self._layout_block_on_page(scaled_block, page, current_pos, font_scale)
-            
+
             if not success:
                 # Block doesn't fit, we're done with this page
                 break
-            
+
+            # Add inter-block spacing after successfully laying out a block
+            # Only add if we're not at the end of the document and there's space
+            if new_pos.block_index < len(self.blocks):
+                page._current_y_offset += self.page_style.inter_block_spacing
+
             # Ensure new position doesn't go beyond bounds
             if new_pos.block_index >= len(self.blocks):
                 # We've reached the end of the document

pyWebLayout/layout/ereader_manager.py

@@ -341,7 +341,97 @@ class EreaderLayoutManager:
     def get_font_scale(self) -> float:
         """Get the current font scale"""
         return self.font_scale
-    
+
+    def increase_line_spacing(self, amount: int = 2) -> Page:
+        """
+        Increase line spacing and re-render current page.
+
+        Args:
+            amount: Pixels to add to line spacing (default: 2)
+
+        Returns:
+            Re-rendered page with increased line spacing
+        """
+        self.page_style.line_spacing += amount
+        self.renderer.page_style = self.page_style  # Update renderer's reference
+        self.renderer.buffer.invalidate_all()  # Clear cache to force re-render
+        return self.get_current_page()
+
+    def decrease_line_spacing(self, amount: int = 2) -> Page:
+        """
+        Decrease line spacing and re-render current page.
+
+        Args:
+            amount: Pixels to remove from line spacing (default: 2)
+
+        Returns:
+            Re-rendered page with decreased line spacing
+        """
+        self.page_style.line_spacing = max(0, self.page_style.line_spacing - amount)
+        self.renderer.page_style = self.page_style  # Update renderer's reference
+        self.renderer.buffer.invalidate_all()  # Clear cache to force re-render
+        return self.get_current_page()
+
+    def increase_inter_block_spacing(self, amount: int = 5) -> Page:
+        """
+        Increase spacing between blocks and re-render current page.
+
+        Args:
+            amount: Pixels to add to inter-block spacing (default: 5)
+
+        Returns:
+            Re-rendered page with increased block spacing
+        """
+        self.page_style.inter_block_spacing += amount
+        self.renderer.page_style = self.page_style  # Update renderer's reference
+        self.renderer.buffer.invalidate_all()  # Clear cache to force re-render
+        return self.get_current_page()
+
+    def decrease_inter_block_spacing(self, amount: int = 5) -> Page:
+        """
+        Decrease spacing between blocks and re-render current page.
+
+        Args:
+            amount: Pixels to remove from inter-block spacing (default: 5)
+
+        Returns:
+            Re-rendered page with decreased block spacing
+        """
+        self.page_style.inter_block_spacing = max(0, self.page_style.inter_block_spacing - amount)
+        self.renderer.page_style = self.page_style  # Update renderer's reference
+        self.renderer.buffer.invalidate_all()  # Clear cache to force re-render
+        return self.get_current_page()
+
+    def increase_word_spacing(self, amount: int = 2) -> Page:
+        """
+        Increase spacing between words and re-render current page.
+
+        Args:
+            amount: Pixels to add to word spacing (default: 2)
+
+        Returns:
+            Re-rendered page with increased word spacing
+        """
+        self.page_style.word_spacing += amount
+        self.renderer.page_style = self.page_style  # Update renderer's reference
+        self.renderer.buffer.invalidate_all()  # Clear cache to force re-render
+        return self.get_current_page()
+
+    def decrease_word_spacing(self, amount: int = 2) -> Page:
+        """
+        Decrease spacing between words and re-render current page.
+
+        Args:
+            amount: Pixels to remove from word spacing (default: 2)
+
+        Returns:
+            Re-rendered page with decreased word spacing
+        """
+        self.page_style.word_spacing = max(0, self.page_style.word_spacing - amount)
+        self.renderer.page_style = self.page_style  # Update renderer's reference
+        self.renderer.buffer.invalidate_all()  # Clear cache to force re-render
+        return self.get_current_page()
+
     def get_table_of_contents(self) -> List[Tuple[str, HeadingLevel, RenderingPosition]]:
         """
         Get the table of contents.

pyWebLayout/style/page_style.py

@@ -14,18 +14,18 @@ class PageStyle:
     border_color: Tuple[int, int, int] = (0, 0, 0)
 
     # Spacing properties
-    line_spacing: int = 5
+    line_spacing: int = 5  # Additional pixels between lines (added to font size)
-    inter_block_spacing: int = 15
+    inter_block_spacing: int = 15  # Pixels between blocks (paragraphs, headings, etc.)
+    word_spacing: int = 0  # Additional pixels between words (0 = use font defaults)
 
     # Padding (top, right, bottom, left)
     padding: Tuple[int, int, int, int] = (20, 20, 20, 20)
 
     # Background color
     background_color: Tuple[int, int, int] = (255, 255, 255)
-    
+
     # Typography properties
     max_font_size: int = 72  # Maximum font size allowed on a page
-    line_spacing_multiplier: float = 1.2  # Baseline-to-baseline spacing multiplier
 
     @property
     def padding_top(self) -> int: