-Document history:
-
- 03/21/2001: Marc Attinasi (attinasi@netscape.com) created document +
- 03/21/2002: Marc Attinasi (attinasi@netscape.com) created document / implementing -moz-force-broken-image-icon for bug -58646 -
+
+58646- + 6/18/2002: David Baron (dbaron@fas.harvard.edu): corrected support + for 'inherit' and '-moz-initial' (didn't test with code, though), + and explained what the final boolean in CheckPropertyData is for. +
- NOTE: This document is still missing a few pieces. I need to + add information on adding to
nsIDOM[NS]CSS2Properties+ andnsDOMCSSDeclaration.
Up front you have to decide some things about the new property:
+ +Questions:
Answers:
There are several places that need to be educated about a new style property. +They are: +
First, add the new name to the property list in nsCSSPropList.h Insert the property in the list alphabetically, using the existing property names as a template. The format of the entry you will create is: +
CSS_PROP(-moz-force-broken-image-iconst, force_broken_image_icons, FRAMECHANGE) // bug 58646-The first value is the formal property name, in other words the property + +
The first value is the formal property name, in other words the property
name as it is seen by the CSS parser.
The second value is the name of the property as it will appear internally.
The last value indicates what must change when the value of the property
changes. It should be one of (
VISUAL, AURAL, REFLOW, CONTENT, FRAMECHANGE
-).
-
-If you need to introduce new constants for the values of the property, they
+).
If you need to introduce new constants for the values of the property, they
must be added to
nsStyleConsts.h
and to the appropriate keyword tables in
@@ -122,13 +128,115 @@ to (or create a new section if you are creating a new style struct). For
this example we will find the 'UserInterface' section and add our new property
there
.
-
// nsCSSUserInterface+
case eCSSProperty_user_input:
case eCSSProperty_user_modify:
case eCSSProperty_user_select:
case eCSSProperty_key_equivalent:
case eCSSProperty_user_focus:
case eCSSProperty_resizer:
case eCSSProperty_cursor:
case eCSSProperty_force_broken_image_icons: {
CSS_ENSURE(UserInterface) {
switch (aProperty) {
case eCSSProperty_user_input: theUserInterface->mUserInput = aValue; break;
case eCSSProperty_user_modify: theUserInterface->mUserModify = aValue; break;
case eCSSProperty_user_select: theUserInterface->mUserSelect = aValue; break;
case eCSSProperty_key_equivalent:
CSS_ENSURE_DATA(theUserInterface->mKeyEquivalent, nsCSSValueList) {
theUserInterface->mKeyEquivalent->mValue = aValue;
CSS_IF_DELETE(theUserInterface->mKeyEquivalent->mNext);
}
break;
case eCSSProperty_user_focus: theUserInterface->mUserFocus = aValue; break;
case eCSSProperty_resizer: theUserInterface->mResizer = aValue; break;
case eCSSProperty_cursor:
CSS_ENSURE_DATA(theUserInterface->mCursor, nsCSSValueList) {
theUserInterface->mCursor->mValue = aValue;
CSS_IF_DELETE(theUserInterface->mCursor->mNext);
}
break;
case eCSSProperty_force_broken_image_icons: theUserInterface->mForceBrokenImageIcon = aValue; break;
CSS_BOGUS_DEFAULT; // make compiler happy
}
}
break;
}
// nsCSSUserInterface
+ case eCSSProperty_user_input:
+ case eCSSProperty_user_modify:
+ case eCSSProperty_user_select:
+ case eCSSProperty_key_equivalent:
+ case eCSSProperty_user_focus:
+ case eCSSProperty_resizer:
+ case eCSSProperty_cursor:
+ case eCSSProperty_force_broken_image_icons: {
+ CSS_ENSURE(UserInterface) {
+ switch (aProperty) {
+ case eCSSProperty_user_input: theUserInterface->mUserInput = aValue; break;
+ case eCSSProperty_user_modify: theUserInterface->mUserModify = aValue; break;
+ case eCSSProperty_user_select: theUserInterface->mUserSelect = aValue; break;
+ case eCSSProperty_key_equivalent:
+ CSS_ENSURE_DATA(theUserInterface->mKeyEquivalent, nsCSSValueList) {
+ theUserInterface->mKeyEquivalent->mValue = aValue;
+ CSS_IF_DELETE(theUserInterface->mKeyEquivalent->mNext);
+ }
+ break;
+ case eCSSProperty_user_focus: theUserInterface->mUserFocus = aValue; break;
+ case eCSSProperty_resizer: theUserInterface->mResizer = aValue; break;
+ case eCSSProperty_cursor:
+ CSS_ENSURE_DATA(theUserInterface->mCursor, nsCSSValueList) {
+ theUserInterface->mCursor->mValue = aValue;
+ CSS_IF_DELETE(theUserInterface->mCursor->mNext);
+ }
+ break;
+ case eCSSProperty_force_broken_image_icons: theUserInterface->mForceBrokenImageIcon = aValue; break;
+
+ CSS_BOGUS_DEFAULT; // make compiler happy
+ }
+ }
+ break;
+ }
+
+
The GetValue method must be similarly modified
:// nsCSSUserInterface+
case eCSSProperty_user_input:
case eCSSProperty_user_modify:
case eCSSProperty_user_select:
case eCSSProperty_key_equivalent:
case eCSSProperty_user_focus:
case eCSSProperty_resizer:
case eCSSProperty_cursor:
case eCSSProperty_force_broken_image_icons: {
CSS_VARONSTACK_GET(UserInterface);
if (nsnull != theUserInterface) {
switch (aProperty) {
case eCSSProperty_user_input: aValue = theUserInterface->mUserInput; break;
case eCSSProperty_user_modify: aValue = theUserInterface->mUserModify; break;
case eCSSProperty_user_select: aValue = theUserInterface->mUserSelect; break;
case eCSSProperty_key_equivalent:
if (nsnull != theUserInterface->mKeyEquivalent) {
aValue = theUserInterface->mKeyEquivalent->mValue;
}
break;
case eCSSProperty_user_focus: aValue = theUserInterface->mUserFocus; break;
case eCSSProperty_resizer: aValue = theUserInterface->mResizer; break;
case eCSSProperty_cursor:
if (nsnull != theUserInterface->mCursor) {
aValue = theUserInterface->mCursor->mValue;
}
break;
case eCSSProperty_force_broken_image_icons: aValue = theUserInterface->mForceBrokenImageIcons; break;
CSS_BOGUS_DEFAULT; // make compiler happy
}
}
else {
aValue.Reset();
}
break;
}
// nsCSSUserInterface
+ case eCSSProperty_user_input:
+ case eCSSProperty_user_modify:
+ case eCSSProperty_user_select:
+ case eCSSProperty_key_equivalent:
+ case eCSSProperty_user_focus:
+ case eCSSProperty_resizer:
+ case eCSSProperty_cursor:
+ case eCSSProperty_force_broken_image_icons: {
+ CSS_VARONSTACK_GET(UserInterface);
+ if (nsnull != theUserInterface) {
+ switch (aProperty) {
+ case eCSSProperty_user_input: aValue = theUserInterface->mUserInput; break;
+ case eCSSProperty_user_modify: aValue = theUserInterface->mUserModify; break;
+ case eCSSProperty_user_select: aValue = theUserInterface->mUserSelect; break;
+ case eCSSProperty_key_equivalent:
+ if (nsnull != theUserInterface->mKeyEquivalent) {
+ aValue = theUserInterface->mKeyEquivalent->mValue;
+ }
+ break;
+ case eCSSProperty_user_focus: aValue = theUserInterface->mUserFocus; break;
+ case eCSSProperty_resizer: aValue = theUserInterface->mResizer; break;
+ case eCSSProperty_cursor:
+ if (nsnull != theUserInterface->mCursor) {
+ aValue = theUserInterface->mCursor->mValue;
+ }
+ break;
+ case eCSSProperty_force_broken_image_icons: aValue = theUserInterface->mForceBrokenImageIcons; break;
+
+ CSS_BOGUS_DEFAULT; // make compiler happy
+ }
+ }
+ else {
+ aValue.Reset();
+ }
+ break;
+ }
+
+
Finally modify
the 'List' method to output the property value.void nsCSSUserInterface::List(FILE* out, PRInt32 aIndent) const+
{
for (PRInt32 index = aIndent; --index >= 0; ) fputs(" ", out);
nsAutoString buffer;
mUserInput.AppendToString(buffer, eCSSProperty_user_input);
mUserModify.AppendToString(buffer, eCSSProperty_user_modify);
mUserSelect.AppendToString(buffer, eCSSProperty_user_select);
nsCSSValueList* keyEquiv = mKeyEquivalent;
while (nsnull != keyEquiv) {
keyEquiv->mValue.AppendToString(buffer, eCSSProperty_key_equivalent);
keyEquiv= keyEquiv->mNext;
}
mUserFocus.AppendToString(buffer, eCSSProperty_user_focus);
mResizer.AppendToString(buffer, eCSSProperty_resizer);
nsCSSValueList* cursor = mCursor;
while (nsnull != cursor) {
cursor->mValue.AppendToString(buffer, eCSSProperty_cursor);
cursor = cursor->mNext;
}
mForceBrokenImageIcon.AppendToString(buffer,eCSSProperty_force_broken_image_icons);
fputs(NS_LossyConvertUCS2toASCII(buffer).get(), out);
}
void nsCSSUserInterface::List(FILE* out, PRInt32 aIndent) const
+{
+ for (PRInt32 index = aIndent; --index >= 0; ) fputs(" ", out);
+
+ nsAutoString buffer;
+
+ mUserInput.AppendToString(buffer, eCSSProperty_user_input);
+ mUserModify.AppendToString(buffer, eCSSProperty_user_modify);
+ mUserSelect.AppendToString(buffer, eCSSProperty_user_select);
+ nsCSSValueList* keyEquiv = mKeyEquivalent;
+ while (nsnull != keyEquiv) {
+ keyEquiv->mValue.AppendToString(buffer, eCSSProperty_key_equivalent);
+ keyEquiv= keyEquiv->mNext;
+ }
+ mUserFocus.AppendToString(buffer, eCSSProperty_user_focus);
+ mResizer.AppendToString(buffer, eCSSProperty_resizer);
+
+ nsCSSValueList* cursor = mCursor;
+ while (nsnull != cursor) {
+ cursor->mValue.AppendToString(buffer, eCSSProperty_cursor);
+ cursor = cursor->mNext;
+ }
+
+ mForceBrokenImageIcon.AppendToString(buffer,eCSSProperty_force_broken_image_icons);
+
+ fputs(NS_LossyConvertUCS2toASCII(buffer).get(), out);
+}
+
+
struct nsStyleUIReset: public nsStyleStruct {
nsStyleUIReset(void);
nsStyleUIReset(const nsStyleUIReset& aOther);
~nsStyleUIReset(void);
NS_DEFINE_STATIC_STYLESTRUCTID_ACCESSOR(eStyleStruct_UIReset)
void* operator new(size_t sz, nsIPresContext* aContext) {
void* result = nsnull;
aContext->AllocateFromShell(sz, &result);
return result;
}
void Destroy(nsIPresContext* aContext) {
this->~nsStyleUIReset();
aContext->FreeToShell(sizeof(nsStyleUIReset), this);
};
PRInt32 CalcDifference(const nsStyleUIReset& aOther) const;
PRUint8 mUserSelect; // [reset] (selection-style)
PRUnichar mKeyEquivalent; // [reset] XXX what type should this be?
PRUint8 mResizer; // [reset]
PRUint8 mForceBrokenImageIcon; // [reset] (0 if not forcing, otherwise forcing)
};
+ struct nsStyleUIReset: public nsStyleStruct {
+ nsStyleUIReset(void);
+ nsStyleUIReset(const nsStyleUIReset& aOther);
+ ~nsStyleUIReset(void);
+
+ NS_DEFINE_STATIC_STYLESTRUCTID_ACCESSOR(eStyleStruct_UIReset)
+
+ void* operator new(size_t sz, nsIPresContext* aContext) {
+ void* result = nsnull;
+ aContext->AllocateFromShell(sz, &result);
+ return result;
+ }
+ void Destroy(nsIPresContext* aContext) {
+ this->~nsStyleUIReset();
+ aContext->FreeToShell(sizeof(nsStyleUIReset), this);
+ };
+
+ PRInt32 CalcDifference(const nsStyleUIReset& aOther) const;
+
+ PRUint8 mUserSelect; // [reset] (selection-style)
+ PRUnichar mKeyEquivalent; // [reset] XXX what type should this be?
+ PRUint8 mResizer; // [reset]
+ PRUint8 mForceBrokenImageIcon; // [reset] (0 if not forcing, otherwise forcing)
+};
+
In the implementation file
nsStyleContext.cpp
add the new data member to the constructors of the style struct and the CalcDifference
method, which must return the correct style-change hint when a change to
your new property is detected. The constructor changes are obvious, but here
is the CalcDifference change for our example:PRInt32 nsStyleUIReset::CalcDifference(const nsStyleUIReset& aOther) const+
{
if (mForceBrokenImageIcon == aOther.mForceBrokenImageIcon) {
if (mResizer == aOther.mResizer) {
if (mUserSelect == aOther.mUserSelect) {
if (mKeyEquivalent == aOther.mKeyEquivalent) {
return NS_STYLE_HINT_NONE;
}
return NS_STYLE_HINT_CONTENT;
}
return NS_STYLE_HINT_VISUAL;
}
return NS_STYLE_HINT_VISUAL;
}
return NS_STYLE_HINT_FRAMECHANGE;
}
PRInt32 nsStyleUIReset::CalcDifference(const nsStyleUIReset& aOther) const
+{
+ if (mForceBrokenImageIcon == aOther.mForceBrokenImageIcon) {
+ if (mResizer == aOther.mResizer) {
+ if (mUserSelect == aOther.mUserSelect) {
+ if (mKeyEquivalent == aOther.mKeyEquivalent) {
+ return NS_STYLE_HINT_NONE;
+ }
+ return NS_STYLE_HINT_CONTENT;
+ }
+ return NS_STYLE_HINT_VISUAL;
+ }
+ return NS_STYLE_HINT_VISUAL;
+ }
+ return NS_STYLE_HINT_FRAMECHANGE;
+}
+
static nsresult+
MapUIForDeclaration(nsCSSDeclaration* aDecl, const nsStyleStructID& aID, nsCSSUserInterface& aUI)
{
if (!aDecl)
return NS_OK; // The rule must have a declaration.
nsCSSUserInterface* ourUI = (nsCSSUserInterface*)aDecl->GetData(kCSSUserInterfaceSID);
if (!ourUI)
return NS_OK; // We don't have any rules for UI.
if (aID == eStyleStruct_UserInterface) {
if (aUI.mUserFocus.GetUnit() == eCSSUnit_Null && ourUI->mUserFocus.GetUnit() != eCSSUnit_Null)
aUI.mUserFocus = ourUI->mUserFocus;
if (aUI.mUserInput.GetUnit() == eCSSUnit_Null && ourUI->mUserInput.GetUnit() != eCSSUnit_Null)
aUI.mUserInput = ourUI->mUserInput;
if (aUI.mUserModify.GetUnit() == eCSSUnit_Null && ourUI->mUserModify.GetUnit() != eCSSUnit_Null)
aUI.mUserModify = ourUI->mUserModify;
if (!aUI.mCursor && ourUI->mCursor)
aUI.mCursor = ourUI->mCursor;
}
else if (aID == eStyleStruct_UIReset) {
if (aUI.mUserSelect.GetUnit() == eCSSUnit_Null && ourUI->mUserSelect.GetUnit() != eCSSUnit_Null)
aUI.mUserSelect = ourUI->mUserSelect;
if (!aUI.mKeyEquivalent && ourUI->mKeyEquivalent)
aUI.mKeyEquivalent = ourUI->mKeyEquivalent;
if (aUI.mResizer.GetUnit() == eCSSUnit_Null && ourUI->mResizer.GetUnit() != eCSSUnit_Null)
aUI.mResizer = ourUI->mResizer;
if (aUI.mForceBrokenImageIcon.GetUnit() == eCSSUnit_Null && ourUI->mForceBrokenImageIcon.GetUnit() == eCSSUnit_Integer)
aUI.mForceBrokenImageIcon = ourUI->mForceBrokenImageIcon;
}
return NS_OK;
}
static nsresult
+MapUIForDeclaration(nsCSSDeclaration* aDecl, const nsStyleStructID& aID, nsCSSUserInterface& aUI)
+{
+ if (!aDecl)
+ return NS_OK; // The rule must have a declaration.
+
+ nsCSSUserInterface* ourUI = (nsCSSUserInterface*)aDecl->GetData(kCSSUserInterfaceSID);
+ if (!ourUI)
+ return NS_OK; // We don't have any rules for UI.
+
+ if (aID == eStyleStruct_UserInterface) {
+ if (aUI.mUserFocus.GetUnit() == eCSSUnit_Null && ourUI->mUserFocus.GetUnit() != eCSSUnit_Null)
+ aUI.mUserFocus = ourUI->mUserFocus;
+
+ if (aUI.mUserInput.GetUnit() == eCSSUnit_Null && ourUI->mUserInput.GetUnit() != eCSSUnit_Null)
+ aUI.mUserInput = ourUI->mUserInput;
+
+ if (aUI.mUserModify.GetUnit() == eCSSUnit_Null && ourUI->mUserModify.GetUnit() != eCSSUnit_Null)
+ aUI.mUserModify = ourUI->mUserModify;
+
+ if (!aUI.mCursor && ourUI->mCursor)
+ aUI.mCursor = ourUI->mCursor;
+
+
+ }
+ else if (aID == eStyleStruct_UIReset) {
+ if (aUI.mUserSelect.GetUnit() == eCSSUnit_Null && ourUI->mUserSelect.GetUnit() != eCSSUnit_Null)
+ aUI.mUserSelect = ourUI->mUserSelect;
+
+ if (!aUI.mKeyEquivalent && ourUI->mKeyEquivalent)
+ aUI.mKeyEquivalent = ourUI->mKeyEquivalent;
+
+ if (aUI.mResizer.GetUnit() == eCSSUnit_Null && ourUI->mResizer.GetUnit() != eCSSUnit_Null)
+ aUI.mResizer = ourUI->mResizer;
+
+ if (aUI.mForceBrokenImageIcon.GetUnit() == eCSSUnit_Null && ourUI->mForceBrokenImageIcon.GetUnit() == eCSSUnit_Integer)
+ aUI.mForceBrokenImageIcon = ourUI->mForceBrokenImageIcon;
+ }
+
+ return NS_OK;
+
+}
+
static const PropertyCheckData UIResetCheckProperties[] = {
CHECKDATA_PROP(nsCSSUserInterface, mUserSelect, CHECKDATA_VALUE, PR_FALSE),
CHECKDATA_PROP(nsCSSUserInterface, mResizer, CHECKDATA_VALUE, PR_FALSE),
CHECKDATA_PROP(nsCSSUserInterface, mKeyEquivalent, CHECKDATA_VALUELIST, PR_FALSE)
CHECKDATA_PROP(nsCSSUserInterface, mForceBrokenImageIcon, CHECKDATA_VALUE, PR_FALSE)
};
+ static const PropertyCheckData UIResetCheckProperties[] = {
+ CHECKDATA_PROP(nsCSSUserInterface, mUserSelect, CHECKDATA_VALUE, PR_FALSE),
+ CHECKDATA_PROP(nsCSSUserInterface, mResizer, CHECKDATA_VALUE, PR_FALSE),
+ CHECKDATA_PROP(nsCSSUserInterface, mKeyEquivalent, CHECKDATA_VALUELIST, PR_FALSE)
+ CHECKDATA_PROP(nsCSSUserInterface, mForceBrokenImageIcon, CHECKDATA_VALUE, PR_FALSE)
+};
+
The first two arguments correspond to the structure and data member from
-teh CSSDeclaration, the third is the data type, the fourth indicates if it
-is a coord value or not....+
// resizer: auto, none, enum, inherit
if (eCSSUnit_Enumerated == uiData.mResizer.GetUnit()) {
ui->mResizer = uiData.mResizer.GetIntValue();
}
else if (eCSSUnit_Auto == uiData.mResizer.GetUnit()) {
ui->mResizer = NS_STYLE_RESIZER_AUTO;
}
else if (eCSSUnit_None == uiData.mResizer.GetUnit()) {
ui->mResizer = NS_STYLE_RESIZER_NONE;
}
else if (eCSSUnit_Inherit == uiData.mResizer.GetUnit()) {
inherited = PR_TRUE;
ui->mResizer = parentUI->mResizer;
}
// force-broken-image-icons: integer
if (eCSSUnit_Integer == uiData.mForceBrokenImageIcons.GetUnit()) {
ui->mForceBrokenImageIcons = uiData.mForceBrokenImageIcons.GetIntValue();
}
if (inherited)
// We inherited, and therefore can't be cached in the rule node. We have to be put right on the
// style context.
aContext->SetStyle(eStyleStruct_UIReset, *ui);
else {
// We were fully specified and can therefore be cached right on the rule node.
if (!aHighestNode->mStyleData.mResetData)
aHighestNode->mStyleData.mResetData = new (mPresContext) nsResetStyleData;
aHighestNode->mStyleData.mResetData->mUIData = ui;
// Propagate the bit down.
PropagateDependentBit(NS_STYLE_INHERIT_UI_RESET, aHighestNode);
}
...
...
+ // resizer: auto, none, enum, inherit
+ if (eCSSUnit_Enumerated == uiData.mResizer.GetUnit()) {
+ ui->mResizer = uiData.mResizer.GetIntValue();
+ }
+ else if (eCSSUnit_Auto == uiData.mResizer.GetUnit()) {
+ ui->mResizer = NS_STYLE_RESIZER_AUTO;
+ }
+ else if (eCSSUnit_None == uiData.mResizer.GetUnit()) {
+ ui->mResizer = NS_STYLE_RESIZER_NONE;
+ }
+ else if (eCSSUnit_Inherit == uiData.mResizer.GetUnit()) {
+ inherited = PR_TRUE;
+ ui->mResizer = parentUI->mResizer;
+ }
+
+ // force-broken-image-icons: integer, inherit, -moz-initial
+ if (eCSSUnit_Integer == uiData.mForceBrokenImageIcons.GetUnit()) {
+ ui->mForceBrokenImageIcons = uiData.mForceBrokenImageIcons.GetIntValue();
+ } else if (eCSSUnit_Inherit == uiData.mForceBrokenImageIcons.GetUnit()) {
+ inherited = PR_TRUE;
+ ui->mForceBrokenImageIcons = parentUI->mForceBrokenImageIcons;
+ } else if (eCSSUnit_Initial == uiData.mForceBrokenImageIcons.GetUnit()) {
+ ui->mForceBrokenImageIcons = 0;
+ }
+
+ if (inherited)
+ // We inherited, and therefore can't be cached in the rule node. We have to be put right on the
+ // style context.
+ aContext->SetStyle(eStyleStruct_UIReset, *ui);
+ else {
+ // We were fully specified and can therefore be cached right on the rule node.
+ if (!aHighestNode->mStyleData.mResetData)
+ aHighestNode->mStyleData.mResetData = new (mPresContext) nsResetStyleData;
+ aHighestNode->mStyleData.mResetData->mUIData = ui;
+ // Propagate the bit down.
+ PropagateDependentBit(NS_STYLE_INHERIT_UI_RESET, aHighestNode);
+ }
+ ...
+
PRBool forceIcon = PR_FALSE;+
const nsStyleUIReset* styleData;
GetStyleData(eStyleStruct_UIReset, (const nsStyleStruct*&) styleData);
if (styleData->mForceBrokenImageIcon) {
forceIcon = PR_TRUE;
}
PRBool forceIcon = PR_FALSE;
+
+ const nsStyleUIReset* styleData;
+ GetStyleData(eStyleStruct_UIReset, (const nsStyleStruct*&) styleData);
+ if (styleData->mForceBrokenImageIcon) {
+ forceIcon = PR_TRUE;
+ }
+
+
Create some testcases with style rules that use the new property, make sure
it is being parsed correctly. Test it in an external stylesheet and in inline
style. Test that it is inherited correctly, or not inherited as appropriate
to your property. Update this document with any further details, or correcting
any errors.