Conversion pipeline: Add option tocontrol the inserted paragraph indent when using the remove blank line between paragraphs option

src/calibre/ebooks/conversion/cli.py

@@ -125,7 +125,7 @@ def add_pipeline_options(parser, plumber):
                       'extra_css',
                       'margin_top', 'margin_left', 'margin_right',
                       'margin_bottom', 'dont_justify',
-                      'insert_blank_line', 'remove_paragraph_spacing',
+                      'insert_blank_line', 'remove_paragraph_spacing','remove_paragraph_spacing_indent_size',
                       'asciiize', 'remove_header', 'header_regex',
                       'remove_footer', 'footer_regex',
                   ]

src/calibre/ebooks/conversion/plumber.py

@@ -309,6 +309,11 @@ OptionRecommendation(name='remove_paragraph_spacing',
         'paragraphs of 1.5em. Spacing removal will not work '
         'if the source file does not use paragraphs (<p> or <div> tags).')
         ),
+        
+OptionRecommendation(name='remove_paragraph_spacing_indent_size',
+        recommended_value=1.5, level=OptionRecommendation.LOW,
+        help=_('Width of the indent used with Remove spacing between paragraphs option')
+        ),        
 
 OptionRecommendation(name='prefer_metadata_cover',
         recommended_value=False, level=OptionRecommendation.LOW,

src/calibre/ebooks/oeb/transforms/flatcss.py

@@ -278,7 +278,7 @@ class CSSFlattener(object):
             if self.context.insert_blank_line:
                 cssdict['margin-top'] = cssdict['margin-bottom'] = '0.5em'
             if self.context.remove_paragraph_spacing:
-                cssdict['text-indent'] = '1.5em'
+                cssdict['text-indent'] =  "%1.1fem" % self.context.remove_paragraph_spacing_indent_size
         if cssdict:
             items = cssdict.items()
             items.sort()

src/calibre/gui2/convert/look_and_feel.py

@@ -23,7 +23,7 @@ class LookAndFeelWidget(Widget, Ui_Form):
                     'font_size_mapping', 'line_height',
                     'linearize_tables',
                     'disable_font_rescaling', 'insert_blank_line',
-                    'remove_paragraph_spacing', 'input_encoding',
+                    'remove_paragraph_spacing', 'remove_paragraph_spacing_indent_size','input_encoding',
                     'asciiize']
                 )
         self.db, self.book_id = db, book_id
@@ -32,6 +32,8 @@ class LookAndFeelWidget(Widget, Ui_Form):
         self.opt_disable_font_rescaling.toggle()
         self.connect(self.button_font_key, SIGNAL('clicked()'),
                 self.font_key_wizard)
+        self.opt_remove_paragraph_spacing.toggle()
+        self.opt_remove_paragraph_spacing.toggle()
 
     def font_key_wizard(self):
         from calibre.gui2.convert.font_key import FontKeyChooser

src/calibre/gui2/convert/look_and_feel.ui

@@ -14,7 +14,7 @@
    <string>Form</string>
   </property>
   <layout class="QGridLayout" name="gridLayout">
-   <item row="0" column="0" colspan="2">
+   <item row="0" column="0">
     <widget class="QCheckBox" name="opt_disable_font_rescaling">
      <property name="text">
       <string>&amp;Disable font size rescaling</string>
@@ -31,7 +31,7 @@
      </property>
     </widget>
    </item>
-   <item row="1" column="3">
+   <item row="1" column="2">
     <widget class="QDoubleSpinBox" name="opt_base_font_size">
      <property name="suffix">
       <string> pt</string>
@@ -63,7 +63,7 @@
      </property>
     </widget>
    </item>
-   <item row="2" column="2" colspan="2">
+   <item row="2" column="1" colspan="2">
     <layout class="QHBoxLayout" name="horizontalLayout">
      <item>
       <widget class="QLineEdit" name="opt_font_size_mapping">
@@ -107,7 +107,7 @@
      </property>
     </widget>
    </item>
-   <item row="3" column="3">
+   <item row="3" column="2">
     <widget class="QDoubleSpinBox" name="opt_line_height">
      <property name="suffix">
       <string> pt</string>
@@ -127,12 +127,59 @@
      </property>
     </widget>
    </item>
+   <item row="4" column="1" colspan="2">
+    <widget class="QLineEdit" name="opt_input_encoding"/>
+   </item>
    <item row="5" column="0" colspan="3">
-    <widget class="QCheckBox" name="opt_remove_paragraph_spacing">
+    <layout class="QHBoxLayout" name="horizontalLayout_3">
-     <property name="text">
+     <item>
-      <string>Remove &amp;spacing between paragraphs</string>
+      <widget class="QCheckBox" name="opt_remove_paragraph_spacing">
-     </property>
+       <property name="text">
-    </widget>
+        <string>Remove &amp;spacing between paragraphs</string>
+       </property>
+      </widget>
+     </item>
+     <item>
+      <spacer name="horizontalSpacer">
+       <property name="orientation">
+        <enum>Qt::Horizontal</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>40</width>
+         <height>20</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
+     <item>
+      <layout class="QHBoxLayout" name="horizontalLayout_2">
+       <item>
+        <widget class="QLabel" name="label_4">
+         <property name="text">
+          <string>Indent size:</string>
+         </property>
+         <property name="alignment">
+          <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QDoubleSpinBox" name="opt_remove_paragraph_spacing_indent_size">
+         <property name="toolTip">
+          <string>&lt;p&gt;When calibre removes inter paragraph spacing, it automatically sets a paragraph indent, to ensure that paragraphs can be easily distinguished. This option controls the width of that indent.</string>
+         </property>
+         <property name="suffix">
+          <string> em</string>
+         </property>
+         <property name="decimals">
+          <number>1</number>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </item>
+    </layout>
    </item>
    <item row="6" column="0">
     <widget class="QCheckBox" name="opt_insert_blank_line">
@@ -155,14 +202,14 @@
      </property>
     </widget>
    </item>
-   <item row="9" column="0" colspan="3">
+   <item row="9" column="0">
     <widget class="QCheckBox" name="opt_asciiize">
      <property name="text">
       <string>&amp;Transliterate unicode characters to ASCII.</string>
      </property>
     </widget>
    </item>
-   <item row="10" column="0" colspan="4">
+   <item row="10" column="0" colspan="3">
     <widget class="QGroupBox" name="groupBox">
      <property name="title">
       <string>Extra &amp;CSS</string>
@@ -174,9 +221,6 @@
      </layout>
     </widget>
    </item>
-   <item row="4" column="2" colspan="2">
-    <widget class="QLineEdit" name="opt_input_encoding"/>
-   </item>
   </layout>
  </widget>
  <resources>
@@ -216,5 +260,37 @@
     </hint>
    </hints>
   </connection>
+  <connection>
+   <sender>opt_remove_paragraph_spacing</sender>
+   <signal>toggled(bool)</signal>
+   <receiver>label_4</receiver>
+   <slot>setEnabled(bool)</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>20</x>
+     <y>20</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>20</x>
+     <y>20</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>opt_remove_paragraph_spacing</sender>
+   <signal>toggled(bool)</signal>
+   <receiver>opt_remove_paragraph_spacing_indent_size</receiver>
+   <slot>setEnabled(bool)</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>20</x>
+     <y>20</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>20</x>
+     <y>20</y>
+    </hint>
+   </hints>
+  </connection>
  </connections>
 </ui>

src/calibre/manual/conversion.rst

@@ -163,7 +163,8 @@ Paragraph spacing
 Normally, paragraphs in XHTML are rendered with a blank line between them and no leading text
 indent. |app| has a couple of options to control this. :guilabel:`Remove spacing between paragraphs`
 forcefully ensure that all paragraphs have no inter paragraph spacing. It also sets the text
-indent to 1.5em to mark that start of every paragraph. :guilabel:`Insert blank line` does the
+indent to 1.5em (can be changed) to mark that start of every paragraph.
+:guilabel:`Insert blank line` does the
 opposite, guaranteeing that there is exactly one blank line between each pair of paragraphs. 
 Both these options are very comprehensive, removing spacing, or inserting it for *all* paragraphs
 (technically <p> and <div> tags). This is so that you can just set the option and be sure that