Only re-render within the visible terminal height

laravel · Apr 3, 2024 · f102cdb · f102cdb
1 parent 0cc41a5
commit f102cdb
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Showing 2 changed files with 10 additions and 62 deletions.
diff --git a/src/Concerns/FakesInputOutput.php b/src/Concerns/FakesInputOutput.php
@@ -27,6 +27,7 @@ public static function fake(array $keys = []): void
         $mock->shouldReceive('restoreTty')->byDefault();
         $mock->shouldReceive('cols')->byDefault()->andReturn(80);
         $mock->shouldReceive('lines')->byDefault()->andReturn(24);
+        $mock->shouldReceive('initDimensions')->byDefault();
 
         foreach ($keys as $key) {
             $mock->shouldReceive('read')->once()->andReturn($key);

diff --git a/src/Prompt.php b/src/Prompt.php
@@ -208,6 +208,8 @@ public static function validateUsing(Closure $callback): void
      */
     protected function render(): void
     {
+        $this->terminal()->initDimensions();
+
         $frame = $this->renderTheme();
 
         if ($frame === $this->prevFrame) {
@@ -223,35 +225,14 @@ protected function render(): void
             return;
         }
 
-        $this->resetCursorPosition();
-
-        // Ensure that the full frame is buffered so subsequent output can see how many trailing newlines were written.
-        if ($this->state === 'submit') {
-            $this->eraseDown();
-            static::output()->write($frame);
+        $terminalHeight = $this->terminal()->lines();
+        $previousFrameHeight = count(explode(PHP_EOL, $this->prevFrame));
+        $renderableLines = array_slice(explode(PHP_EOL, $frame), abs(min(0, $terminalHeight - $previousFrameHeight)));
 
-            $this->prevFrame = '';
-
-            return;
-        }
-
-        $diff = $this->diffLines($this->prevFrame, $frame);
-
-        if (count($diff) === 1) { // Update the single line that changed.
-            $diffLine = $diff[0];
-            $this->moveCursor(0, $diffLine);
-            $this->eraseLines(1);
-            $lines = explode(PHP_EOL, $frame);
-            static::output()->write($lines[$diffLine]);
-            $this->moveCursor(0, count($lines) - $diffLine - 1);
-        } elseif (count($diff) > 1) { // Re-render everything past the first change
-            $diffLine = $diff[0];
-            $this->moveCursor(0, $diffLine);
-            $this->eraseDown();
-            $lines = explode(PHP_EOL, $frame);
-            $newLines = array_slice($lines, $diffLine);
-            static::output()->write(implode(PHP_EOL, $newLines));
-        }
+        $this->moveCursorToColumn(1);
+        $this->moveCursorUp(min($terminalHeight, $previousFrameHeight) - 1);
+        $this->eraseDown();
+        $this->output()->write(implode(PHP_EOL, $renderableLines));
 
         $this->prevFrame = $frame;
     }
@@ -268,40 +249,6 @@ protected function submit(): void
         }
     }
 
-    /**
-     * Reset the cursor position to the beginning of the previous frame.
-     */
-    private function resetCursorPosition(): void
-    {
-        $lines = count(explode(PHP_EOL, $this->prevFrame)) - 1;
-
-        $this->moveCursor(-999, $lines * -1);
-    }
-
-    /**
-     * Get the difference between two strings.
-     *
-     * @return array<int>
-     */
-    private function diffLines(string $a, string $b): array
-    {
-        if ($a === $b) {
-            return [];
-        }
-
-        $aLines = explode(PHP_EOL, $a);
-        $bLines = explode(PHP_EOL, $b);
-        $diff = [];
-
-        for ($i = 0; $i < max(count($aLines), count($bLines)); $i++) {
-            if (! isset($aLines[$i]) || ! isset($bLines[$i]) || $aLines[$i] !== $bLines[$i]) {
-                $diff[] = $i;
-            }
-        }
-
-        return $diff;
-    }
-
     /**
      * Handle a key press and determine whether to continue.
      */