Textarea resize-able only to larger; min-height and min-width properly set

Source/core/rendering/RenderLayerScrollableArea.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 56 matching lines @@
 #include "platform/graphics/GraphicsContextStateSaver.h"
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/scroll/ScrollAnimator.h"
 #include "platform/scroll/ScrollbarTheme.h"
 #include "public/platform/Platform.h"
 
 namespace WebCore {
 
 const int ResizerControlExpandRatioForTouch = 2;
 
+// Default value is set to 15 as the default
+// minimum size used by firefox is 15x15.
+static const int defaultMinimumWidthForResizing = 15;
+static const int defaultMinimumHeightForResizing = 15;
+
 RenderLayerScrollableArea::RenderLayerScrollableArea(RenderBox& box)
     : m_box(box)
     , m_inResizeMode(false)
     , m_scrollsOverflow(false)
     , m_scrollDimensionsDirty(true)
     , m_inOverflowRelayout(false)
     , m_needsCompositedScrolling(false)
     , m_forceNeedsCompositedScrolling(DoNotForceCompositedScrolling)
     , m_scrollCorner(0)
     , m_resizer(0)
@@ skipping 620 matching lines @@
 static bool overflowRequiresScrollbar(EOverflow overflow)
 {
     return overflow == OSCROLL;
 }
 
 static bool overflowDefinesAutomaticScrollbar(EOverflow overflow)
 {
     return overflow == OAUTO || overflow == OOVERLAY;
 }
 
+IntSize RenderLayerScrollableArea::minimumSizeForResizing()
+{
+    int minimumWidth;
+    int minimumHeight;

[Julien - ping for review, 2014/04/29 22:13:54]

No need for C89 style declaration. It's better to just declare and initialize
them at the same time below.

[harpreet.sk, 2014/04/30 10:12:53]

Done.

+
+    minimumWidth = intValueForLength(m_box.style()->logicalMinWidth(), m_box.containingBlock()->logicalWidth());
+    minimumHeight = intValueForLength(m_box.style()->logicalMinHeight(), m_box.containingBlock()->logicalHeight());
+
+    minimumWidth = std::max(minimumWidth, defaultMinimumWidthForResizing);
+    minimumHeight = std::max(minimumHeight, defaultMinimumHeightForResizing);
+    return IntSize(minimumWidth, minimumHeight);
+}
+
 void RenderLayerScrollableArea::updateAfterStyleChange(const RenderStyle* oldStyle)
 {
     // List box parts handle the scrollbars by themselves so we have nothing to do.
     if (m_box.style()->appearance() == ListboxPart)
         return;
 
     // RenderView shouldn't provide scrollbars on its own.
     if (m_box.isRenderView())
         return;
 
@@ skipping 618 matching lines @@
         ASSERT_NOT_REACHED();
     }
 
     float zoomFactor = m_box.style()->effectiveZoom();
 
     LayoutSize newOffset = offsetFromResizeCorner(document.view()->windowToContents(pos));
     newOffset.setWidth(newOffset.width() / zoomFactor);
     newOffset.setHeight(newOffset.height() / zoomFactor);
 
     LayoutSize currentSize = LayoutSize(m_box.width() / zoomFactor, m_box.height() / zoomFactor);
-    LayoutSize minimumSize = element->minimumSizeForResizing().shrunkTo(currentSize);
-    element->setMinimumSizeForResizing(minimumSize);
 
     LayoutSize adjustedOldOffset = LayoutSize(oldOffset.width() / zoomFactor, oldOffset.height() / zoomFactor);
     if (m_box.style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft()) {
         newOffset.setWidth(-newOffset.width());
         adjustedOldOffset.setWidth(-adjustedOldOffset.width());
     }
 
-    LayoutSize difference = (currentSize + newOffset - adjustedOldOffset).expandedTo(minimumSize) - currentSize;
+    LayoutSize difference = (currentSize + newOffset - adjustedOldOffset).expandedTo(LayoutSize(minimumSizeForResizing())) - currentSize;

[Julien - ping for review, 2014/04/29 22:13:54]

Do we really need this explicit conversion? If we really do it, it seems better
to just change minimumSizeForResizing() to return a LayoutSize (with a FIXME
that it's not right but this code is confused).

[harpreet.sk, 2014/04/30 10:12:53]

I cross checked that expandTo() takes LayoutSize as argument so i thought of
converting it but it's working fine even if we pass IntSize so i had rmeove this
explicit conversion.

 
     bool isBoxSizingBorder = m_box.style()->boxSizing() == BORDER_BOX;
 
     EResize resize = m_box.style()->resize();
     if (resize != RESIZE_VERTICAL && difference.width()) {
         if (element->isFormControlElement()) {
             // Make implicit margins from the theme explicit (see <http://bugs.webkit.org/show_bug.cgi?id=9547>).
             element->setInlineStyleProperty(CSSPropertyMarginLeft, m_box.marginLeft() / zoomFactor, CSSPrimitiveValue::CSS_PX);
             element->setInlineStyleProperty(CSSPropertyMarginRight, m_box.marginRight() / zoomFactor, CSSPrimitiveValue::CSS_PX);
         }
@@ skipping 147 matching lines @@
 void RenderLayerScrollableArea::setForceNeedsCompositedScrolling(ForceNeedsCompositedScrollingMode mode)
 {
     if (m_forceNeedsCompositedScrolling == mode)
         return;
 
     m_forceNeedsCompositedScrolling = mode;
     layer()->didUpdateNeedsCompositedScrolling();
 }
 
 } // Namespace WebCore