WIP add detect Lists function

src/javascript/models/AppState.jsx

@@ -5,6 +5,7 @@ import RemoveRepetitiveElements from './transformations/RemoveRepetitiveElements
 import VerticalToHorizontal from './transformations/VerticalToHorizontal.jsx';
 import DetectPdfBlocks from './transformations/DetectPdfBlocks.jsx'
 import DetectTOC from './transformations/DetectTOC.jsx'
+import DetectLists from './transformations/DetectLists.jsx'
 import DetectCodeBlocks from './transformations/DetectCodeBlocks.jsx'
 import DetectFormats from './transformations/DetectFormats.jsx'
 import CombineSameY from './transformations/CombineSameY.jsx';
@@ -31,6 +32,7 @@ export default class AppState {
             new VerticalToHorizontal(),
             new DetectPdfBlocks(),
             new DetectTOC(),
+            new DetectLists(),
             new DetectCodeBlocks(),
             // new DetectFormats(),
             // new CombineSameY(),

src/javascript/models/MarkdownElements.jsx

@@ -1,6 +1,8 @@
 import PdfBlock from './BlockPage.jsx';
 
 export const HEADLINE1 = "Headline 1";
+export const PARAGRAPH = "Paragraph";
+export const LIST_BLOCK = "List";
 export const CODE_BLOCK = "Code/Quote";
 export const TOC_BLOCK = "TOC";
 

src/javascript/models/TextItemCombiner.jsx

@@ -20,11 +20,19 @@ export default class TextItemCombiner {
                 var text = '';
                 var maxHeight = 0;
                 var widthSum = 0;
+                var lastItem;
                 itemGroup.forEach(item => {
                     // item.annotation = REMOVED_ANNOTATION;
                     // resultItems.push(item);
+                    if (lastItem && !text.endsWith(' ') && !item.text.startsWith(' ')) {
+                        const xDistance = item.x - lastItem.x - lastItem.width;
+                        if (xDistance >= 5) {
+                            text += ' ';
+                        }
+                    }
                     text += item.text;
                     widthSum += item.width;
+                    lastItem = item;
                 });
                 //TODO set other elements
                 resultItems.push(new TextItem({

src/javascript/models/transformations/DetectCodeBlocks.jsx

@@ -5,18 +5,19 @@ import PdfBlock from '../PdfBlock.jsx';
 import TextItemCombiner from '../TextItemCombiner.jsx';
 import { REMOVED_ANNOTATION, ADDED_ANNOTATION } from '../Annotation.jsx';
 import { CODE_BLOCK } from '../MarkdownElements.jsx';
+import { minXFromBlocks } from '../../textItemFunctions.jsx';
 
 //Detect quotes, code etc.. which is transformed to markdown code syntax
 export default class DetectCodeBlocks extends ToPdfBlockViewTransformation {
 
     constructor() {
-        super("Detect Code Blocks");
+        super("Detect Code/Quotes");
     }
 
     createSummaryView(parseResult:ParseResult) {
         return <div>
                  Detected
-                 { ' ' + parseResult.summary.foundBlocks + ' ' } blocks.
+                 { ' ' + parseResult.summary.foundBlocks + ' ' } code/quote blocks.
                </div>;
     }
 
@@ -27,14 +28,8 @@ export default class DetectCodeBlocks extends ToPdfBlockViewTransformation {
         const textCombiner = new TextItemCombiner({});
 
         parseResult.content.forEach(page => {
-            var minX = 999;
-            page.blocks.forEach(block => {
-                block.textItems.forEach(item => {
-                    minX = Math.min(minX, item.x)
-                });
-            });
-
-            if (minX < 999) {
+            var minX = minXFromBlocks(page.blocks);
+            if (minX) {
                 const itemAreSuitable = (items) => {
                     for ( let item of items ) {
                         if (item.x == minX) {

src/javascript/models/transformations/DetectLists.jsx

@@ -0,0 +1,148 @@
+import React from 'react';
+import ToPdfBlockViewTransformation from './ToPdfBlockViewTransformation.jsx';
+import ParseResult from '../ParseResult.jsx';
+import TextItem from '../TextItem.jsx';
+import PdfBlock from '../PdfBlock.jsx';
+import TextItemCombiner from '../TextItemCombiner.jsx';
+import { REMOVED_ANNOTATION, ADDED_ANNOTATION } from '../Annotation.jsx';
+import { PARAGRAPH, LIST_BLOCK } from '../MarkdownElements.jsx';
+import { minXFromBlocks } from '../../textItemFunctions.jsx';
+
+//Detect quotes, code etc.. which is transformed to markdown code syntax
+export default class DetectLists extends ToPdfBlockViewTransformation {
+
+    constructor() {
+        super("Detect Lists");
+    }
+
+    createSummaryView(parseResult:ParseResult) {
+        return <div>
+                 Detected
+                 { ' ' + parseResult.summary.foundBlocks + ' ' } list blocks.
+               </div>;
+    }
+
+    transform(parseResult:ParseResult) {
+        var foundBlocks = 0;
+        const textCombiner = new TextItemCombiner({});
+
+        parseResult.content.forEach(page => {
+            var minX = minXFromBlocks(page.blocks);
+            if (minX) {
+                const newBlocks = [];
+                page.blocks.forEach(block => {
+                    newBlocks.push(block);
+                    if (!block.type) {
+                        const yGroupedItems = textCombiner.combine(block.textItems);
+                        if (hasMoreThan2LineItems(yGroupedItems)) {
+                            block.annotation = REMOVED_ANNOTATION;
+                            foundBlocks++;
+
+                            var lastItemX;
+                            var currentLevel = 0;
+                            var itemsBeforeFirstLineItem = [];
+                            var listBlockItems = [];
+                            var xByLevel = {};
+
+                            const pushLineItem = (originalItem, text, setLevel) => {
+                                if (lastItemX && setLevel) {
+                                    if (originalItem.x > lastItemX) {
+                                        currentLevel++;
+                                        xByLevel[originalItem.x] = currentLevel;
+                                    } else if (originalItem.x < lastItemX) {
+                                        currentLevel = xByLevel[originalItem.x];
+                                    }
+                                } else {
+                                    xByLevel[originalItem.x] = 0;
+                                }
+
+
+                                listBlockItems.push(new TextItem({
+                                    ...originalItem,
+                                    text: ' '.repeat(currentLevel * 3) + text
+                                }));
+                                lastItemX = originalItem.x;
+
+                            };
+
+                            yGroupedItems.forEach(lineItem => {
+                                if (isPlainListItem(lineItem.text)) {
+                                    var text = lineItem.text;
+                                    text = text.substring(1, text.length).trim();
+                                    text = '- ' + text;
+                                    pushLineItem(lineItem, text, true);
+
+                                } else if (isNumberedListItem(lineItem.text)) {
+                                    var numberedText = lineItem.text;
+                                    numberedText
+                                    pushLineItem(lineItem, numberedText, true);
+                                } else {
+                                    if (lastItemX) {
+                                        pushLineItem(lineItem, lineItem.text, false);
+                                    } else {
+                                        itemsBeforeFirstLineItem.push(lineItem);
+                                    }
+                                }
+                            });
+
+                            if (itemsBeforeFirstLineItem.length > 0) {
+                                newBlocks.push(new PdfBlock({
+                                    textItems: itemsBeforeFirstLineItem,
+                                    type: PARAGRAPH,
+                                    annotation: ADDED_ANNOTATION
+                                }));
+                            }
+                            //TODO display with whitespace pre support
+                            newBlocks.push(new PdfBlock({
+                                textItems: listBlockItems,
+                                type: LIST_BLOCK,
+                                annotation: ADDED_ANNOTATION
+                            }));
+                        }
+                    }
+                });
+                page.blocks = newBlocks;
+            }
+        });
+
+        return new ParseResult({
+            ...parseResult,
+            summary: {
+                foundBlocks: foundBlocks
+            }
+        });
+
+    }
+
+}
+
+function hasMoreThan2LineItems(textItems:TextItem[]) {
+    var numberOfListItemLineStarts = 0;
+    for ( let item of textItems ) {
+        if (isPlainListItem(item.text) || isNumberedListItem(item.text)) {
+            numberOfListItemLineStarts++;
+            if (numberOfListItemLineStarts == 2) {
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+function isPlainListItem(string) {
+    if (string.startsWith('-')) {
+        return true;
+    }
+    if (string.startsWith('•')) {
+        return true;
+    }
+    return false;
+}
+
+function isNumberedListItem(string) {
+    if (!isNaN(parseInt(string.charAt(0)))) {
+        return true;
+    }
+    return false;
+}
+

src/javascript/models/transformations/DetectPdfBlocks.jsx

@@ -3,6 +3,7 @@ import ToPdfBlockViewTransformation from './ToPdfBlockViewTransformation.jsx';
 import ParseResult from '../ParseResult.jsx';
 import PdfBlockPage from '../PdfBlockPage.jsx';
 import PdfBlock from '../PdfBlock.jsx';
+import { minXFromTextItems } from '../../textItemFunctions.jsx';
 
 export default class DetectPdfBlocks extends ToPdfBlockViewTransformation {
 
@@ -21,6 +22,7 @@ export default class DetectPdfBlocks extends ToPdfBlockViewTransformation {
         const {mostUsedDistance} = parseResult.globals;
         var createdBlocks = 0;
         const newContent = parseResult.content.map(page => {
+            var minX = minXFromTextItems(page.textItems);
             const blocks = [];
             var textItemsInBlock = [];
             const completBlock = () => {
@@ -31,9 +33,9 @@ export default class DetectPdfBlocks extends ToPdfBlockViewTransformation {
             };
             var lastItem;
             page.textItems.forEach(item => {
+
                 if (lastItem) {
-                    const distance = lastItem.y - item.y;
-                    if (distance < 0 - mostUsedDistance / 2 || distance > mostUsedDistance) {
+                    if (shouldSplit(lastItem, item, minX, mostUsedDistance)) {
                         completBlock();
                     }
                 }
@@ -59,3 +61,20 @@ export default class DetectPdfBlocks extends ToPdfBlockViewTransformation {
     }
 
 }
+
+function shouldSplit(lastItem, item, minX, mostUsedDistance) {
+    const distance = lastItem.y - item.y;
+    if (distance < 0 - mostUsedDistance / 2) {
+        //distance is negative - and not only a bit
+        return true;
+    }
+    var allowedDisctance = mostUsedDistance + 1;
+    if (lastItem.x == item.x && item.x > minX) {
+        //intended elements like lists often have greater spacing
+        allowedDisctance = mostUsedDistance + mostUsedDistance / 2;
+    }
+    if (distance > allowedDisctance) {
+        return true;
+    }
+    return false;
+}

src/javascript/models/transformations/ToMarkdown.jsx

@@ -18,7 +18,7 @@ export default class ToMarkdown extends Transformation {
         var text = '';
         parseResult.content.forEach(page => {
             page.blocks.forEach((block) => {
-                text += block.text + '\n\n';
+                text += block.text + '\n';
             });
         });
         return new ParseResult({

src/javascript/textItemFunctions.jsx

@@ -0,0 +1,26 @@
+import PdfBlock from './models/PdfBlock.jsx';
+import TextItem from './models/TextItem.jsx';
+
+export function minXFromBlocks(blocks:PdfBlock[]) {
+    var minX = 999;
+    blocks.forEach(block => {
+        block.textItems.forEach(item => {
+            minX = Math.min(minX, item.x)
+        });
+    });
+    if (minX == 999) {
+        return null;
+    }
+    return minX;
+}
+
+export function minXFromTextItems(items:TextItem) {
+    var minX = 999;
+    items.forEach(item => {
+        minX = Math.min(minX, item.x)
+    });
+    if (minX == 999) {
+        return null;
+    }
+    return minX;
+}