[Console] use ANSI escape sequences in ProgressBar overwrite method

Author: alekitto

src/Symfony/Component/Console/Helper/ProgressBar.php

@@ -40,7 +40,6 @@ class ProgressBar
     private $startTime;
     private $stepWidth;
     private $percent = 0.0;
-    private $lastMessagesLength = 0;
     private $formatLineCount;
     private $messages;
     private $overwrite = true;
@@ -472,7 +471,7 @@ public function clear()
             $this->setRealFormat($this->internalFormat ?: $this->determineBestFormat());
         }
 
-        $this->overwrite(str_repeat("\n", $this->formatLineCount));
+        $this->overwrite('');
     }
 
     /**
@@ -512,37 +511,22 @@ private function setMaxSteps($max)
      */
     private function overwrite($message)
     {
-        $lines = explode("\n", $message);
-
-        // append whitespace to match the line's length
-        if (null !== $this->lastMessagesLength) {
-            foreach ($lines as $i => $line) {
-                if ($this->lastMessagesLength > Helper::strlenWithoutDecoration($this->output->getFormatter(), $line)) {
-                    $lines[$i] = str_pad($line, $this->lastMessagesLength, "\x20", STR_PAD_RIGHT);
-                }
-            }
-        }
-
         if ($this->overwrite) {
-            // move back to the beginning of the progress bar before redrawing it
+            // Move the cursor to the beginning of the line
             $this->output->write("\x0D");
-        } elseif ($this->step > 0) {
-            // move to new line
-            $this->output->writeln('');
-        }
 
-        if ($this->formatLineCount) {
-            $this->output->write(sprintf("\033[%dA", $this->formatLineCount));
-        }
-        $this->output->write(implode("\n", $lines));
+            // Erase the line
+            $this->output->write("\x1B[2K");
 
-        $this->lastMessagesLength = 0;
-        foreach ($lines as $line) {
-            $len = Helper::strlenWithoutDecoration($this->output->getFormatter(), $line);
-            if ($len > $this->lastMessagesLength) {
-                $this->lastMessagesLength = $len;
+            // Erase previous lines
+            if ($this->formatLineCount > 0) {
+                $this->output->write(str_repeat("\x1B[1A\x1B[2K", $this->formatLineCount));
             }
+        } elseif ($this->step > 0) {
+            $this->output->writeln('');
         }
+
+        $this->output->write($message);
     }
 
     private function determineBestFormat()

src/Symfony/Component/Console/Tests/Helper/ProgressBarTest.php

@@ -233,7 +233,7 @@ public function testOverwriteWithShorterLine()
             $this->generateOutput('  0/50 [>---------------------------]   0%').
             $this->generateOutput('  0/50 [>---------------------------]   0%').
             $this->generateOutput('  1/50 [>---------------------------]   2%').
-            $this->generateOutput('  2/50 [=>--------------------------]     '),
+            $this->generateOutput('  2/50 [=>--------------------------]'),
             stream_get_contents($output->getStream())
         );
     }
@@ -356,7 +356,7 @@ public function testClear()
         $this->assertEquals(
             $this->generateOutput('  0/50 [>---------------------------]   0%').
             $this->generateOutput(' 25/50 [==============>-------------]  50%').
-            $this->generateOutput('                                          '),
+            $this->generateOutput(''),
             stream_get_contents($output->getStream())
         );
     }
@@ -554,9 +554,9 @@ public function testMultilineFormat()
         rewind($output->getStream());
         $this->assertEquals(
             $this->generateOutput(">---------------------------\nfoobar").
-            $this->generateOutput("=========>------------------\nfoobar                      ").
-            $this->generateOutput("                            \n                            ").
-            $this->generateOutput("============================\nfoobar                      "),
+            $this->generateOutput("=========>------------------\nfoobar").
+            "\x0D\x1B[2K\x1B[1A\x1B[2K".
+            $this->generateOutput("============================\nfoobar"),
             stream_get_contents($output->getStream())
         );
     }
@@ -665,6 +665,6 @@ protected function generateOutput($expected)
     {
         $count = substr_count($expected, "\n");
 
-        return "\x0D".($count ? sprintf("\033[%dA", $count) : '').$expected;
+        return "\x0D\x1B[2K".($count ? str_repeat("\x1B[1A\x1B[2K", $count) : '').$expected;
     }
 }