Remove caching of style sheets in IE6 (cache may be invalid when there are multiple modules)
Review at http://gwt-code-reviews.appspot.com/159804
Review by: jgw@google.com
git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@7694 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/dom/client/StyleElement.java b/user/src/com/google/gwt/dom/client/StyleElement.java
index 0a1da64..9f3e3d6 100644
--- a/user/src/com/google/gwt/dom/client/StyleElement.java
+++ b/user/src/com/google/gwt/dom/client/StyleElement.java
@@ -40,6 +40,13 @@
}
/**
+ * The CSS text.
+ */
+ public final native String getCssText() /*-{
+ return this.cssText;
+ }-*/;
+
+ /**
* Enables/disables the style sheet.
* @deprecated use {@link #isDisabled()} instead
*/
@@ -73,6 +80,13 @@
}-*/;
/**
+ * Sets the CSS text.
+ */
+ public final native void setCssText(String cssText) /*-{
+ this.cssText = cssText;
+ }-*/;
+
+ /**
* Enables/disables the style sheet.
*/
public final native void setDisabled(boolean disabled) /*-{
diff --git a/user/src/com/google/gwt/dom/client/StyleInjector.java b/user/src/com/google/gwt/dom/client/StyleInjector.java
index c1dabcd..673d6ac 100644
--- a/user/src/com/google/gwt/dom/client/StyleInjector.java
+++ b/user/src/com/google/gwt/dom/client/StyleInjector.java
@@ -17,8 +17,6 @@
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.JavaScriptObject;
-import com.google.gwt.core.client.JsArray;
-import com.google.gwt.core.client.JsArrayInteger;
import com.google.gwt.core.client.JsArrayString;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
@@ -85,14 +83,29 @@
*/
public static class StyleInjectorImplIE extends StyleInjectorImpl {
- /*
- * TODO(bobv) : Talk to scottb about being able to read this out of the
- * module xml file as a configuration-property to handle cases where
- * multiple GWT modules are living in the same page.
+ /**
+ * The maximum number of style tags that can be handled by IE.
*/
private static final int MAX_STYLE_SHEETS = 30;
- private static final JsArray<StyleElement> STYLE_ELEMENTS = JavaScriptObject.createArray().cast();
- private static final JsArrayInteger STYLE_ELEMENT_LENGTHS = JavaScriptObject.createArray().cast();
+
+ /**
+ * A cache of the lengths of the current style sheets. A value of 0
+ * indicates that the length has not yet been retrieved.
+ */
+ private static int[] styleSheetLengths = new int[MAX_STYLE_SHEETS];
+
+ private static native int getDocumentStyleCount() /*-{
+ return $doc.styleSheets.length;
+ }-*/;
+
+ private static native StyleElement getDocumentStyleSheet(int index) /*-{
+ return $doc.styleSheets[index];
+ }-*/;
+
+ private static native int getDocumentStyleSheetLength(int index) /*-{
+ return $doc.styleSheets[index].cssText.length;
+ }-*/;
+
public native void appendContents(StyleElement style, String contents) /*-{
style.cssText += contents;
@@ -100,89 +113,81 @@
@Override
public StyleElement injectStyleSheet(String contents) {
- int idx = STYLE_ELEMENTS.length();
- if (getDocumentStyleCount() < MAX_STYLE_SHEETS) {
+ int numStyles = getDocumentStyleCount();
+ if (numStyles < MAX_STYLE_SHEETS) {
// Just create a new style element and add it to the list
- StyleElement style = createElement();
- setContents(style, contents);
- STYLE_ELEMENTS.set(idx, style);
- STYLE_ELEMENT_LENGTHS.set(idx, contents.length());
- return style;
+ return createNewStyleSheet(contents);
} else {
/*
* Find shortest style element to minimize re-parse time in the general
* case.
+ *
+ * We cache the lengths of the style sheets in order to avoid expensive
+ * calls to retrieve their actual contents. Note that if another module
+ * or script makes changes to the style sheets that we are unaware of,
+ * the worst that will happen is that we will choose a style sheet to
+ * append to that is not actually of minimum size.
*/
int shortestLen = Integer.MAX_VALUE;
int shortestIdx = -1;
- for (int i = 0; i < idx; i++) {
- if (STYLE_ELEMENT_LENGTHS.get(i) < shortestLen) {
- shortestLen = STYLE_ELEMENT_LENGTHS.get(i);
+ for (int i = 0; i < numStyles; i++) {
+ int len = styleSheetLengths[i];
+ if (len == 0) {
+ // Cache the length
+ len = styleSheetLengths[i] = getDocumentStyleSheetLength(i);
+ }
+ if (len <= shortestLen) {
+ shortestLen = len;
shortestIdx = i;
}
}
-
- /**
- * This assertion can fail if the max number of style elements exist
- * before this module can inject any style elements, so STYLE_ELEMENTS
- * will be empty. However, the fix would degrade performance for the
- * general case. TODO(jlabanca): Can we handle this scenario
- * efficiently?
- */
- assert shortestIdx != -1;
-
- StyleElement style = STYLE_ELEMENTS.get(shortestIdx);
- STYLE_ELEMENT_LENGTHS.set(shortestIdx, shortestLen + contents.length());
- appendContents(style, contents);
- return style;
+ styleSheetLengths[shortestIdx] += contents.length();
+ return appendToStyleSheet(shortestIdx, contents, true);
}
}
@Override
public StyleElement injectStyleSheetAtEnd(String contents) {
- if (STYLE_ELEMENTS.length() == 0) {
- return injectStyleSheet(contents);
+ int documentStyleCount = getDocumentStyleCount();
+ if (documentStyleCount == 0) {
+ return createNewStyleSheet(contents);
}
-
- int idx = STYLE_ELEMENTS.length() - 1;
- StyleElement style = STYLE_ELEMENTS.get(idx);
- STYLE_ELEMENT_LENGTHS.set(idx, STYLE_ELEMENT_LENGTHS.get(idx)
- + contents.length());
- appendContents(style, contents);
-
- return style;
+
+ return appendToStyleSheet(documentStyleCount - 1, contents, true);
}
@Override
public StyleElement injectStyleSheetAtStart(String contents) {
- if (STYLE_ELEMENTS.length() == 0) {
- return injectStyleSheet(contents);
+ if (getDocumentStyleCount() == 0) {
+ return createNewStyleSheet(contents);
}
-
- StyleElement style = STYLE_ELEMENTS.get(0);
- STYLE_ELEMENT_LENGTHS.set(0, STYLE_ELEMENT_LENGTHS.get(0)
- + contents.length());
- prependContents(style, contents);
-
- return style;
+
+ return appendToStyleSheet(0, contents, false); // prepend
}
public native void prependContents(StyleElement style, String contents) /*-{
style.cssText = contents + style.cssText;
}-*/;
- @Override
- public native void setContents(StyleElement style, String contents) /*-{
- style.cssText = contents;
- }-*/;
+ private StyleElement appendToStyleSheet(int idx, String contents, boolean append) {
+ StyleElement style = getDocumentStyleSheet(idx);
+ if (append) {
+ appendContents(style, contents);
+ } else {
+ prependContents(style, contents);
+ }
+ return style;
+ }
private native StyleElement createElement() /*-{
return $doc.createStyleSheet();
}-*/;
- private native int getDocumentStyleCount() /*-{
- return $doc.styleSheets.length;
- }-*/;
+ private StyleElement createNewStyleSheet(String contents) {
+ StyleElement style = createElement();
+ style.setCssText(contents);
+ return style;
+ }
}
private static final JsArrayString toInject = JavaScriptObject.createArray().cast();
