From 826999acc66391eab23fe2348ff62f3a8af04f9c Mon Sep 17 00:00:00 2001
From: Brian Ewins <brian.ewins@gmail.com>
Date: Sat, 18 Apr 2009 21:38:45 +0100
Subject: [PATCH] Fix bug 3188, text selection across table cells

Bug 3188. When selecting text, poppler goes across the whole
page then down, rather than across each cell, down that cell,
then across to the next cell. This leads to illegible paste
results.

Teach TextPage to visit the selection in reading order rather than
block order. Start with the first block in reading order whose
bottom right lies below and right of either the start or end point
of the selection. Finish at the first block containing the other
selection point, or if there is no such block, at the first block
below the selection.
---
 poppler/TextOutputDev.cc |  118 ++++++++++++++++++++++++++-------------------
 1 files changed, 68 insertions(+), 50 deletions(-)

diff --git a/poppler/TextOutputDev.cc b/poppler/TextOutputDev.cc
index c0599ce..c7c1041 100644
--- a/poppler/TextOutputDev.cc
+++ b/poppler/TextOutputDev.cc
@@ -3934,73 +3934,91 @@ void TextPage::visitSelection(TextSelectionVisitor *visitor,
 			      PDFRectangle *selection,
 			      SelectionStyle style)
 {
-  int i, begin, end;
   PDFRectangle child_selection;
   double start_x, start_y, stop_x, stop_y;
-  TextBlock *b;
+  TextFlow *flow, *first_flow;
+  TextBlock *blk, *first_block, *low_block, *last_block, *stop_block;
+
+  first_flow = NULL;
+  first_block = NULL;
+  low_block = NULL;
+  last_block = NULL;
+  stop_block = NULL;
 
-  begin = nBlocks;
-  end = 0;
   start_x = selection->x1;
   start_y = selection->y1;
   stop_x = selection->x2;
   stop_y = selection->y2;
 
-  for (i = 0; i < nBlocks; i++) {
-    b = blocks[i];
-
-    if (selection->x1 < b->xMax && selection->y1 < b->yMax &&
-	selection->x2 < b->xMax && selection->y2 < b->yMax && i < begin) {
-      begin = i;
-      if (selection->y1 < selection->y2) {
-	start_x = selection->x1;
-	start_y = selection->y1;
-	stop_x = selection->x2;
-	stop_y = selection->y2;
-      } else {
-	start_x = selection->x2;
-	start_y = selection->y2;
-	stop_x = selection->x1;
-	stop_y = selection->y1;
+  for (flow = flows; flow && !stop_block; flow = flow->next) {
+    for (blk = flow->blocks; blk && !stop_block; blk = blk->next) {
+      if (!first_block) {
+	if (selection->x1 < blk->xMax &&
+	    selection->y1 < blk->yMax &&
+	    (selection->x2 >= blk->xMax ||
+	     selection->y2 >= blk->yMax ||
+	     selection->y1 < selection->y2)) {
+	  first_block = blk;
+	  first_flow = flow;
+	} else if (selection->x2 < blk->xMax && 
+		   selection->y2 < blk->yMax) {
+	  start_x = selection->x2;
+	  start_y = selection->y2;
+	  stop_x = selection->x1;
+	  stop_y = selection->y1;
+	  first_block = blk;
+	  first_flow = flow;
+	}
+      }
+      if (first_block) {
+	if (!low_block && stop_y < blk->yMin) {
+	  low_block = blk;
+	}
+	if (stop_x > blk->xMin &&
+	    stop_y > blk->yMin &&
+	    stop_x < blk->xMax &&
+	    stop_y < blk->yMax) {
+	  stop_block = blk;
+	  last_block = stop_block->next;
+	  // this assumes flows are never empty.
+	  if (!last_block && flow->next) {
+	    last_block = flow->next->blocks;
+	  }
+	}       
       }
-    } else if (selection->x1 < b->xMax && selection->y1 < b->yMax && i < begin) {
-      begin = i;
-      start_x = selection->x1;
-      start_y = selection->y1;
-      stop_x = selection->x2;
-      stop_y = selection->y2;
-    } else if (selection->x2 < b->xMax && selection->y2 < b->yMax && i < begin) {
-      begin = i;
-      start_x = selection->x2;
-      start_y = selection->y2;
-      stop_x = selection->x1;
-      stop_y = selection->y1;
     }
-
-    if ((selection->x1 > b->xMin && selection->y1 > b->yMin) ||
-	(selection->x2 > b->xMin && selection->y2 > b->yMin))
-      end = i + 1;
   }
-
-  for (i = begin; i < end; i++) {
-    if (blocks[i]->xMin < start_x && start_x < blocks[i]->xMax &&
-	blocks[i]->yMin < start_y && start_y < blocks[i]->yMax) {
-      child_selection.x1 = start_x;
-      child_selection.y1 = start_y;
+  if (!first_block) {
+    return;
+  }
+  if (!stop_block) {
+    // this happens when the stop point is not in a block.
+    last_block = low_block;
+  }
+  for (flow = first_flow; flow; flow = flow->next) {
+    if (flow == first_flow) {
+      blk = first_block;
     } else {
+      blk = flow->blocks;
+    }
+    for (; blk; blk = blk->next) {
+      if (blk == last_block) {
+	return;
+      }
       child_selection.x1 = 0;
       child_selection.y1 = 0;
-    }
-    if (blocks[i]->xMin < stop_x && stop_x < blocks[i]->xMax &&
-	blocks[i]->yMin < stop_y && stop_y < blocks[i]->yMax) {
-      child_selection.x2 = stop_x;
-      child_selection.y2 = stop_y;
-    } else {
       child_selection.x2 = pageWidth;
       child_selection.y2 = pageHeight;
+      if (blk == first_block) {
+	child_selection.x1 = start_x;
+	child_selection.y1 = start_y;
+      }
+      if (blk == stop_block) {
+	child_selection.x2 = stop_x;
+	child_selection.y2 = stop_y;
+      }
+      blk->visitSelection(visitor, &child_selection, style);
     }
-
-    blocks[i]->visitSelection(visitor, &child_selection, style);
   }
 }
 
-- 
1.6.2.2