office-gobmx/svx
Mike Kaganski 6362c905cf tdf#143514: Avoid double-free in dbgutil code
SdrObject::Free may start a chain of deletions, removing more
than one object from maAllIncarnatedObjects. Trying to free
them for the second time after that would lead to crash.

Change-Id: I8648b05d167acecb2799ecf165c387721528a11a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/119433
Tested-by: Mike Kaganski <mike.kaganski@collabora.com>
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
2021-07-23 20:06:49 +02:00
..
doc
inc
qa Move svl::Items to include/svl/whichranges.hxx, and unify its usage 2021-07-19 16:33:01 +02:00
sdi
source tdf#143514: Avoid double-free in dbgutil code 2021-07-23 20:06:49 +02:00
uiconfig/ui resave with latest glade 2021-07-15 15:07:49 +02:00
util
AllLangMoTarget_svx.mk
CppunitTest_svx_dialogs_test.mk
CppunitTest_svx_gallery_test.mk
CppunitTest_svx_removewhichrange.mk
CppunitTest_svx_unit.mk
Executable_gengal.mk
IwyuFilter_svx.yaml
JunitTest_svx_unoapi.mk
Library_svx.mk
Library_svxcore.mk
Library_textconversiondlgs.mk
Makefile
Module_svx.mk
Package_gengal.mk
README.md
UIConfig_svx.mk
UITest_svx_table.mk

Graphics Related Helper Code

Contains graphics related helper code. Lots of the draw and impress code is in this shared library.

  • xoutdev

    this is where a lot of wht work would happen to move to the canvas. (what does that mean?)

  • svdraw

    transparent gradient stuff. [seriously? surely much more, too]

SdrObject

The shapes you can see in LibreOffice (like rectangle, etc.) are SdrObjects. They are declared as a hierarchy:

SdrObject <- SdrAttrObj <- E3dObject <- E3dCompoundObject <- E3dCubeObj
    ^ ^ ^             ^            ^              | | ^ ^
    | | |             |            |              | | | +--- E3dExtrudeObj
    | | |             |            |              | | +----- E3dLatheObj
    | | |             |            |              | +------- E3dPolygonObj
    | | |             |            |              +--------- E3dSphereObj
    | | |             |            +--- E3dScene...
    | | |             |
    | | |             +--- SdrTextObj <- SdrObjCustomShape...
    | | |                   ^ ^ ^ ^ ^
    | | |                   | | | | +--- SdrEdgeObj...
    | | |                   | | | +----- SdrMeasureObj...
    | | |                   | | +------- SdrPathObj...
    | | |                   | +--------- SdrRectObj...
    | | |                   +----------- SdrTableObj...
    | | +--- SdrObjGroup...
    | + ---- SdrPageObj...
    +------- SdrVirtObj...

The above is incomplete of course.

SdrModel / SdrView

Copied from svdview.hxx:

First of all the app creates a SdrModel. Then it opens a Win and creates a SdrView. ShowSdrPage() announces a page at SdrView. It's possible to show SdrView in any Wins at once.

SdrView can show as many Wins as it wants at once. Pages are announced or checked out with the help of ShowSdrPage()/HideSdrPage(). For every announced page there is a SdrPageView instance in container aPages. If more than one page is showed, you have to pay attention that the offset parameter of ShowSdrPage() is conformed to the size of the page (to prevent overlapping of two pages).

SdrView itself is inherited from many objects in a chain of inheritance (all that starts with SdrPaintView - that is itself inherited from few classes too):

SdrPaintView <- SdrSnapView <- SdrMarkView <- SdrEditView <- SdrPolyEditView
                                                                 ^
+----------------------------------------------------------------+
|
SdrGlueEditView <- SdrObjEditView <- SdrExchangeView <- SdrDragView
                                                                 ^
+----------------------------------------------------------------+
|
SdrCreateView <- SdrView

From SdrView on, it is not flat, but a real hierarchy again.

Drawing Layer / SdrObject(s)

See drawinglayer/README.md for general information about drawinglayer.

Below is the class diagram that comes from http://www.openoffice.org/marketing/ooocon2006/presentations/wednesday_g11.odp, slide number 6.

.------- Model --------------.      .------- View -----------------------------------------.
| SdrObject - ViewContact    | 1..* | ViewObjectContact                                    |
|              getChild()    |------|    getPrimitiveList()  -----> Object(s) ---> SdrView |
|              getVOC()      |      |    getRecPrimitiveList()      Contact                |
|              getViewInd... |      |________|_____________________________________________|
| ...ependentPrimitiveList() |               |
|____________________________|            generates
                                             |           ______
                                             V          /      |
                                   .----------------------.    |
                                   | basePrimitive        |    |
                                   |   getRange()         |<---'
                                   |   getDecomposition() |
                                   |______________________|

For SdrObjects, there are own DrawingLayer primitives in svx/source/sdr/primitive2d

The ViewContact / ViewObject / ViewObjectContact are in svx/source/sdr/contact Decomposes the SdrObjects, and does all sort of operations on them.

If the number of visualizable objects (e.g. SdrObjects) is X, and the number of SdrViews is Y, then:

  • there are X ViewContact instances (1:1 relation with a visualizable object)
  • there are Y ObjectContact instances (1:1 relation with an SdrView)
  • there are X*Y ViewObjecContact instances (1:N relation to both visualizable objects and SdrViews)