/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */
#include "nsHTMLContainerFrame.h"
#include "nsIRenderingContext.h"
#include "nsIPresContext.h"
#include "nsIPresShell.h"
#include "nsIStyleContext.h"
#include "nsStyleConsts.h"
#include "nsCSSRendering.h"
#include "nsIContent.h"
#include "nsLayoutAtoms.h"
#include "nsIWidget.h"
#include "nsILinkHandler.h"
#include "nsHTMLValue.h"
#include "nsGUIEvent.h"
#include "nsIDocument.h"
#include "nsIURL.h"
#include "nsIPtr.h"
#include "nsPlaceholderFrame.h"
#include "nsIHTMLContent.h"
#include "nsHTMLParts.h"
#include "nsIView.h"
#include "nsIViewManager.h"
#include "nsViewsCID.h"
#include "nsIReflowCommand.h"
#include "nsHTMLIIDs.h"
#include "nsDOMEvent.h"
#include "nsIScrollableView.h"
#include "nsWidgetsCID.h"
#include "nsIStyleSet.h"
#include "nsCOMPtr.h"

static NS_DEFINE_IID(kScrollViewIID, NS_ISCROLLABLEVIEW_IID);
static NS_DEFINE_IID(kCChildCID, NS_CHILD_CID);

NS_IMETHODIMP
nsHTMLContainerFrame::Paint(nsIPresContext& aPresContext,
                            nsIRenderingContext& aRenderingContext,
                            const nsRect& aDirtyRect,
                            nsFramePaintLayer aWhichLayer)
{
  if (NS_FRAME_IS_UNFLOWABLE & mState) {
    return NS_OK;
  }
  if (NS_FRAME_PAINT_LAYER_BACKGROUND == aWhichLayer) {
    const nsStyleDisplay* disp = (const nsStyleDisplay*)
      mStyleContext->GetStyleData(eStyleStruct_Display);
    if (disp->mVisible && mRect.width && mRect.height) {
      // Paint our background and border
      PRIntn skipSides = GetSkipSides();
      const nsStyleColor* color = (const nsStyleColor*)
        mStyleContext->GetStyleData(eStyleStruct_Color);
      const nsStyleSpacing* spacing = (const nsStyleSpacing*)
        mStyleContext->GetStyleData(eStyleStruct_Spacing);

      nsRect  rect(0, 0, mRect.width, mRect.height);
      nsCSSRendering::PaintBackground(aPresContext, aRenderingContext, this,
                                      aDirtyRect, rect, *color, *spacing, 0, 0);
      nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, this,
                                  aDirtyRect, rect, *spacing, mStyleContext, skipSides);
      nsCSSRendering::PaintOutline(aPresContext, aRenderingContext, this,
                                  aDirtyRect, rect, *spacing, mStyleContext, 0);
    }
  }

  // Now paint the kids. Note that child elements have the opportunity to
  // override the visibility property and display even if their parent is
  // hidden
  PaintChildren(aPresContext, aRenderingContext, aDirtyRect, aWhichLayer);
  return NS_OK;
}

/**
 * Create a next-in-flow for aFrame. Will return the newly created
 * frame in aNextInFlowResult <b>if and only if</b> a new frame is
 * created; otherwise nsnull is returned in aNextInFlowResult.
 */
nsresult
nsHTMLContainerFrame::CreateNextInFlow(nsIPresContext& aPresContext,
                                       nsIFrame* aOuterFrame,
                                       nsIFrame* aFrame,
                                       nsIFrame*& aNextInFlowResult)
{
  aNextInFlowResult = nsnull;

  nsIFrame* nextInFlow;
  aFrame->GetNextInFlow(&nextInFlow);
  if (nsnull == nextInFlow) {
    // Create a continuation frame for the child frame and insert it
    // into our lines child list.
    nsIFrame* nextFrame;
    aFrame->GetNextSibling(&nextFrame);

    nsIPresShell* presShell;
    nsIStyleSet*  styleSet;
    aPresContext.GetShell(&presShell);
    presShell->GetStyleSet(&styleSet);
    NS_RELEASE(presShell);
    styleSet->CreateContinuingFrame(&aPresContext, aFrame, aOuterFrame, &nextInFlow);
    NS_RELEASE(styleSet);

    if (nsnull == nextInFlow) {
      return NS_ERROR_OUT_OF_MEMORY;
    }
    aFrame->SetNextSibling(nextInFlow);
    nextInFlow->SetNextSibling(nextFrame);

    NS_FRAME_LOG(NS_FRAME_TRACE_NEW_FRAMES,
       ("nsHTMLContainerFrame::MaybeCreateNextInFlow: frame=%p nextInFlow=%p",
        aFrame, nextInFlow));

    aNextInFlowResult = nextInFlow;
  }
  return NS_OK;
}

static nsresult
ReparentFrameViewTo(nsIFrame*       aFrame,
                    nsIViewManager* aViewManager,
                    nsIView*        aNewParentView,
                    nsIView*        aOldParentView)
{
  nsIView*  view;

  // Does aFrame have a view?
  aFrame->GetView(&view);
  if (view) {
#ifdef NS_DEBUG
    // Verify that the current parent view is what we think it is
    nsIView*  parentView;

    view->GetParent(parentView);
    NS_ASSERTION(parentView == aOldParentView, "unexpected parent view");
#endif

    // Change the parent view.
    PRInt32 zIndex;
    view->GetZIndex(zIndex);
    aViewManager->RemoveChild(aOldParentView, view);
    
    // XXX We need to insert this view in the correct place within its z-order...
    aViewManager->InsertChild(aNewParentView, view, zIndex);

  } else {
    // Iterate the child frames, and check each child frame to see if it has
    // a view
    nsIFrame* childFrame;

    aFrame->FirstChild(nsnull, &childFrame);
    while (childFrame) {
      ReparentFrameViewTo(childFrame, aViewManager, aNewParentView, aOldParentView);
      childFrame->GetNextSibling(&childFrame);
    }
  }

  return NS_OK;
}

// Helper function that returns the nearest view to this frame. Checks
// this frame, its parent frame, its parent frame, ...
static nsIView*
GetClosestViewFor(nsIFrame* aFrame)
{
  NS_PRECONDITION(aFrame, "null frame pointer");
  nsIView*  view;

  do {
    aFrame->GetView(&view);
    if (view) {
      break;
    }
    aFrame->GetParent(&aFrame);
  } while (aFrame);

  NS_POSTCONDITION(view, "no containing view");
  return view;
}

nsresult
nsHTMLContainerFrame::ReparentFrameView(nsIFrame* aChildFrame,
                                        nsIFrame* aOldParentFrame,
                                        nsIFrame* aNewParentFrame)
{
  NS_PRECONDITION(aChildFrame, "null child frame pointer");
  NS_PRECONDITION(aOldParentFrame, "null old parent frame pointer");
  NS_PRECONDITION(aNewParentFrame, "null new parent frame pointer");
  NS_PRECONDITION(aOldParentFrame != aNewParentFrame, "same old and new parent frame");

  nsIView*  childView;
  nsIView*  oldParentView;
  nsIView*  newParentView;
  
  // This code is called often and we need it to be as fast as possible, so
  // see if we can trivially detect that no work needs to be done
  aChildFrame->GetView(&childView);
  if (!childView) {
    // Child frame doesn't have a view. See if it has any child frames
    nsIFrame* firstChild;
    aChildFrame->FirstChild(nsnull, &firstChild);
    if (!firstChild) {
      return NS_OK;
    }
  }

  // See if either the old parent frame or the new parent frame have a view
  aOldParentFrame->GetView(&oldParentView);
  aNewParentFrame->GetView(&newParentView);

  if (!oldParentView && !newParentView) {
    // Walk up both the old parent frame and the new parent frame nodes
    // stopping when we either find a common parent or views for one
    // or both of the frames.
    //
    // This works well in the common case where we push/pull and the old parent
    // frame and the new parent frame are part of the same flow. They will
    // typically be the same distance (height wise) from the
    do {
      aOldParentFrame->GetParent(&aOldParentFrame);
      aNewParentFrame->GetParent(&aNewParentFrame);
      
      // We should never walk all the way to the root frame without finding
      // a view
      NS_ASSERTION(aOldParentFrame && aNewParentFrame, "didn't find view");

      // See if we reached a common parent
      if (aOldParentFrame == aNewParentFrame) {
        break;
      }

      // Get the views
      aOldParentFrame->GetView(&oldParentView);
      aNewParentFrame->GetView(&newParentView);
    } while (!(oldParentView || newParentView));
  }


  // See if we found a common parent frame
  if (aOldParentFrame == aNewParentFrame) {
    // We found a common parent and there are no views between the old parent
    // and the common parent or the new parent frame and the common parent.
    // Because neither the old parent frame nor the new parent frame have views,
    // then any child views don't need reparenting
    return NS_OK;
  }

  // We found views for one or both of the parent frames before we found a
  // common parent
  NS_ASSERTION(oldParentView || newParentView, "internal error");
  if (!oldParentView) {
    oldParentView = GetClosestViewFor(aOldParentFrame);
  }
  if (!newParentView) {
    newParentView = GetClosestViewFor(aNewParentFrame);
  }
  
  // See if the old parent frame and the new parent frame are in the
  // same view sub-hierarchy. If they are then we don't have to do
  // anything
  if (oldParentView != newParentView) {
    nsCOMPtr<nsIViewManager>  viewManager;
    oldParentView->GetViewManager(*getter_AddRefs(viewManager));

    // They're not so we need to reparent any child views
    return ReparentFrameViewTo(aChildFrame, viewManager, newParentView,
                               oldParentView);
  }

  return NS_OK;
}

nsresult
nsHTMLContainerFrame::CreateViewForFrame(nsIPresContext& aPresContext,
                                         nsIFrame* aFrame,
                                         nsIStyleContext* aStyleContext,
                                         PRBool aForce)
{
  nsIView* view;
  aFrame->GetView(&view);
  // If we don't yet have a view, see if we need a view
  if (nsnull == view) {
    PRInt32 zIndex = 0;
    PRBool  fixedBackgroundAttachment = PR_FALSE;

    // Get nsStyleColor and nsStyleDisplay
    const nsStyleColor* color = (const nsStyleColor*)
      aStyleContext->GetStyleData(eStyleStruct_Color);
    const nsStyleDisplay* display = (const nsStyleDisplay*)
      aStyleContext->GetStyleData(eStyleStruct_Display);

    if (color->mOpacity != 1.0f) {
      NS_FRAME_LOG(NS_FRAME_TRACE_CALLS,
        ("nsHTMLContainerFrame::CreateViewForFrame: frame=%p opacity=%g",
         aFrame, color->mOpacity));
      aForce = PR_TRUE;
    }

    // See if the frame has a fixed background attachment
    if (NS_STYLE_BG_ATTACHMENT_FIXED == color->mBackgroundAttachment) {
      aForce = PR_TRUE;
      fixedBackgroundAttachment = PR_TRUE;
    }
    
    // See if the frame is being relatively positioned or absolutely
    // positioned
    if (!aForce) {
      const nsStylePosition* position = (const nsStylePosition*)
        aStyleContext->GetStyleData(eStyleStruct_Position);

      if (NS_STYLE_POSITION_RELATIVE == position->mPosition) {
        NS_FRAME_LOG(NS_FRAME_TRACE_CALLS,
          ("nsHTMLContainerFrame::CreateViewForFrame: frame=%p relatively positioned",
           aFrame));
        aForce = PR_TRUE;
        
        // Get the z-index to use
        if (position->mZIndex.GetUnit() == eStyleUnit_Integer) {
          zIndex = position->mZIndex.GetIntValue();
        }
      
      } else if (position->IsAbsolutelyPositioned()) {
        NS_FRAME_LOG(NS_FRAME_TRACE_CALLS,
          ("nsHTMLContainerFrame::CreateViewForFrame: frame=%p relatively positioned",
           aFrame));
        aForce = PR_TRUE;

        // Get the z-index to use
        if (position->mZIndex.GetUnit() == eStyleUnit_Integer) {
          zIndex = position->mZIndex.GetIntValue();
        }

        // XXX CSS2 says clip applies to block-level and replaced elements with
        // overflow set to other than 'visible'. Where should this go?
#if 0
        // Is there a clip rect specified?
        nsViewClip    clip = {0, 0, 0, 0};
        PRUint8       clipType = (display->mClipFlags & NS_STYLE_CLIP_TYPE_MASK);
        nsViewClip*   pClip = nsnull;

        if (NS_STYLE_CLIP_RECT == clipType) {
          if ((NS_STYLE_CLIP_LEFT_AUTO & display->mClipFlags) == 0) {
            clip.mLeft = display->mClip.left;
          }
          if ((NS_STYLE_CLIP_RIGHT_AUTO & display->mClipFlags) == 0) {
            clip.mRight = display->mClip.right;
          }
          if ((NS_STYLE_CLIP_TOP_AUTO & display->mClipFlags) == 0) {
            clip.mTop = display->mClip.top;
          }
          if ((NS_STYLE_CLIP_BOTTOM_AUTO & display->mClipFlags) == 0) {
            clip.mBottom = display->mClip.bottom;
          }
          pClip = &clip;
        }
        else if (NS_STYLE_CLIP_INHERIT == clipType) {
          // XXX need to handle clip inherit (get from parent style context)
          NS_NOTYETIMPLEMENTED("clip inherit");
        }
#endif
      }
    }

    // See if the frame is a scrolled frame
    if (!aForce) {
      nsIAtom*  pseudoTag;
      aStyleContext->GetPseudoType(pseudoTag);
      if (pseudoTag == nsLayoutAtoms::scrolledContentPseudo) {
        NS_FRAME_LOG(NS_FRAME_TRACE_CALLS,
          ("nsHTMLContainerFrame::CreateViewForFrame: scrolled frame=%p", aFrame));
        aForce = PR_TRUE;
      }
      NS_IF_RELEASE(pseudoTag);
    }

    if (aForce) {
      // Create a view
      nsIFrame* parent;

      aFrame->GetParentWithView(&parent);
      NS_ASSERTION(parent, "GetParentWithView failed");
      nsIView* parentView;
   
      parent->GetView(&parentView);
      NS_ASSERTION(parentView, "no parent with view");

      // Create a view
      static NS_DEFINE_IID(kViewCID, NS_VIEW_CID);
      static NS_DEFINE_IID(kIViewIID, NS_IVIEW_IID);

      nsresult result = nsComponentManager::CreateInstance(kViewCID, 
                                                     nsnull, 
                                                     kIViewIID, 
                                                     (void **)&view);
      if (NS_OK == result) {
        nsIViewManager* viewManager;
        parentView->GetViewManager(viewManager);
        NS_ASSERTION(nsnull != viewManager, "null view manager");

        // Initialize the view
        nsRect bounds;
        aFrame->GetRect(bounds);
        view->Init(viewManager, bounds, parentView);

        // If the frame has a fixed background attachment, then indicate that the
        // view's contents should repainted and not bitblt'd
        if (fixedBackgroundAttachment) {
          PRUint32  viewFlags;
          view->GetViewFlags(&viewFlags);
          view->SetViewFlags(viewFlags | NS_VIEW_PUBLIC_FLAG_DONT_BITBLT);
        }
        
        // Insert the view into the view hierarchy. If the parent view is a
        // scrolling view we need to do this differently
        nsIScrollableView*  scrollingView;
        if (NS_SUCCEEDED(parentView->QueryInterface(kScrollViewIID, (void**)&scrollingView))) {
          scrollingView->SetScrolledView(view);
        } else {
          viewManager->InsertChild(parentView, view, zIndex);
        }

        // If the background color is transparent or the visibility is hidden
        // then mark the view as having transparent content.
        // XXX We could try and be smarter about this and check whether there's
        // a background image. If there is a background image and the image is
        // fully opaque then we don't need to mark the view as having transparent
        // content...
        if ((NS_STYLE_BG_COLOR_TRANSPARENT & color->mBackgroundFlags) ||
            !display->mVisible) {
          viewManager->SetViewContentTransparency(view, PR_TRUE);
        }

        // Set the initial visiblity of the view -EDV
        view->SetVisibility(NS_STYLE_VISIBILITY_HIDDEN == display->mVisible ? nsViewVisibility_kHide : nsViewVisibility_kShow);

        // XXX If it's relatively positioned or absolutely positioned then we
        // need to mark it as having transparent content, too. See bug #2502
        const nsStylePosition* position = (const nsStylePosition*)
          aStyleContext->GetStyleData(eStyleStruct_Position);

        // XXX Michael: uncomment this code to test the problem I described...
        if ((NS_STYLE_POSITION_RELATIVE == position->mPosition) ||
            (NS_STYLE_POSITION_ABSOLUTE == position->mPosition)) {
          viewManager->SetViewContentTransparency(view, PR_TRUE);
        }

        // XXX If it's fixed positioned, then create a widget so it floats
        // above the scrolling area
        if (NS_STYLE_POSITION_FIXED == position->mPosition) {
          view->CreateWidget(kCChildCID);
        }

        viewManager->SetViewOpacity(view, color->mOpacity);
        NS_RELEASE(viewManager);
      }

      // Remember our view
      aFrame->SetView(view);

      NS_FRAME_LOG(NS_FRAME_TRACE_CALLS,
        ("nsHTMLContainerFrame::CreateViewForFrame: frame=%p view=%p",
         aFrame));
      return result;
    }
  }
  return NS_OK;
}