xdiff : side by side support with screen width parameter

git-svn-id: https://svn.fournier38.fr/svn/ProgSVN/trunk@5062 bf3deb0d-5f1a-0410-827f-c0cc1f45334c

Tests/xdiffTest.php

@@ -8,7 +8,6 @@
 class test_xdiff extends PHPUnit_Framework_TestCase
 {
   // Declaration of $string1 and $string2
-  // Taken from 
   // {{{
   private $string1 = "This part of the
 document has stayed the
@@ -336,4 +335,48 @@ to this document.
     $this->setExpectedException ();
     $res = $xdiff->diffFile ("/tmp/test_xdiff1", "/tmp/test_xdiffNOTEXISTS");
   }
+
+  public function test_diffFile_sideBySide_1 ()
+  {
+    file_put_contents ("/tmp/test_xdiff1", $this->string1);
+    file_put_contents ("/tmp/test_xdiff2", $this->string2);
+    $xdiff = new xdiff ("sideBySide");
+    $res = $xdiff->diffFile ("/tmp/test_xdiff1", "/tmp/test_xdiff2");
+    $this->assertSame ($res,
+"							      >	This is an important
+							      >	notice! It should
+							      >	therefore be located at
+							      >	the beginning of this
+							      >	document!
+							      >
+This part of the						This part of the
+document has stayed the						document has stayed the
+same from version to						same from version to
+version.  It shouldn't						version.  It shouldn't
+be shown if it doesn't						be shown if it doesn't
+change.  Otherwise, that					change.  Otherwise, that
+would not be helping to						would not be helping to
+compress the size of the					compress the size of the
+changes.							changes.
+
+This paragraph contains					      <
+text that is outdated.					      <
+It will be deleted in the				      <
+near future.						      <
+							      <
+It is important to spell					It is important to spell
+check this dokument. On					      |	check this document. On
+the other hand, a						the other hand, a
+misspelled word isn't						misspelled word isn't
+the end of the world.						the end of the world.
+Nothing in the rest of						Nothing in the rest of
+this paragraph needs to						this paragraph needs to
+be changed. Things can						be changed. Things can
+be added after it.						be added after it.
+							      >
+							      >	This paragraph contains
+							      >	important new additions
+							      >	to this document.
+");
+  }
 }

xdiff.php

@@ -29,6 +29,14 @@ class xdiff
     */
   private $output = null;
 
+  /** Define the size of one column in side by side mode
+    * 62 chars by default
+    * The maximum width used on screen is 2*$s2sWidth+2 (134 by default)
+    * The value must validate $s2sWidth = 8 * X - 2 (with X is integer), like
+    * 6, 14, 22, 30, 38, 46, 54, 62, 70, 78, 86, 94, 102
+    */
+  private $s2sWidth = 62;
+
   /** The constructor allow to choose the output.
     * @param string $output The output mode [normal|unified]
     */
@@ -43,6 +51,24 @@ class xdiff
   }
   // }}}
 
+  /** Allow to set the side by side width to the maximum allowed by screenWidth
+    * @param integer $screenWidth The maximum width of the screen
+    */
+  public function setScreenWidth ($screenWidth)
+  // {{{
+  {
+    for ($x = 20 ; $x > 0 ; $x--)
+    {
+      $s2sWidth = 8 * $x - 2;
+      if (2*$s2sWidth+2 <= $screenWidth)
+      {
+        $this->s2sWidth = $s2sWidth;
+        break;
+      }
+    }
+  }
+  // }}}
+
   /** Compute the differences between two strings $string1 and $string2
     * @param string $string1 The first string to compare
     * @param string $string2 The second string to compare
@@ -356,6 +382,94 @@ class xdiff
   }
   // }}}
 
+  /** Return a string like "diff -y" (Side by Side)
+    * @param array $diffArray The diff array analyzed by diffArray method
+    * @return string
+    */
+  private function displaySideBySide ($diffArray)
+  // {{{
+  {
+    $d = "";
+    $i = 0 ;
+    while ($i < count ($diffArray))
+    {
+      $diff = $diffArray[$i];
+      $i++;
+      if ($diff["type"] === "Equal")
+      {
+        foreach ($diff["chunk"] as $line)
+          $d .= $this->side ($line, $line);
+      }
+      elseif ($diff["type"] === "Append")
+      {
+        foreach ($diff["chunk"] as $line)
+          $d .= $this->side ("", $line, ">");
+      }
+      elseif ($diff["type"] === "Delete")
+      {
+        foreach ($diff["chunk"] as $line)
+          $d .= $this->side ($line, "", "<");
+      }
+      elseif ($diff["type"] === "Change")
+      {
+        $x = 0;
+        $y = 0;
+        while (key_exists ($x, $diff["chunk1"]) ||
+               key_exists ($y, $diff["chunk2"]))
+        {
+          $side1 = (key_exists ($x, $diff["chunk1"])) ?
+            $diff["chunk1"][$x] : "";
+          $side2 = (key_exists ($y, $diff["chunk2"])) ?
+            $diff["chunk2"][$y] : "";
+          $d .= $this->side ($side1, $side2, "|");
+          if ($side1 !== "")
+            $x++;
+          if ($side2 !== "")
+            $y++;
+        }
+      }
+    }
+    return $d;
+  }
+  // }}}
+
+  /** Return a string sideBySide. Used by displaySideBySide for each line
+    * @param string $side1 The string to be displayed on side1
+    * @param string $side2 The string to be displayed on side2
+    * @param string|null $symbol The symbol used to present the diff (<>|)
+    */
+  private function side ($side1, $side2, $symbol = null)
+  // {{{
+  {
+    $d = "";
+    if (! is_string ($side1))
+      throw new \Exception ("XDiff : side1 parameter not a string");
+    if (! is_string ($side2))
+      throw new \Exception ("XDiff : side2 parameter not a string");
+    if (trim ($symbol) === "")
+      $symbol = null;
+    $side1 = mb_substr (rtrim ($side1), 0, $this->s2sWidth - 1);
+    $side2 = mb_substr (rtrim ($side2), 0, $this->s2sWidth - 1);
+    $d .= $side1;
+    $nbtabs = floor ((1 + $this->s2sWidth - mb_strlen ($side1)) / 8);
+    if ($symbol !== null || $side2 !== "")
+      $d .= str_repeat ("\t", $nbtabs);
+    if ($side1 !== "" && $symbol === null)
+      $d .= "\t";
+    elseif ($symbol !== null)
+    {
+      if (mb_strlen ($side1) < $this->s2sWidth - 1)
+        $d .= str_repeat (" ", 5);
+      $d .= " ".$symbol;
+    }
+    if ($symbol !== null && $side2 !== "")
+      $d .= "\t";
+    $d .= $side2;
+    $d .= "\n";
+    return $d;
+  }
+  // }}}
+
   /** This function return the next common part between both arrays starting at
     * position $i for $array1 and $j for array2
     * Return empty string if no common lines was found