scrollercomponent.java

一个虚拟训练系统.主要使用j2ee框架实现.

            case ACTION_NEXT:
                facetName = "next";
                linkText = "Next";
                break;
            case ACTION_PREVIOUS:
                facetName = "previous";
                linkText = "Previous";
                break;
            default:
                facetName = "number";
                linkText = "" + navActionType;
                isPageNumber = true;
                // heuristic: if navActionType is number, and we are not
                // enabled, this must be the current page.
                if (!enabled) {
                    facetName = "current";
                    isCurrentPage = true;
                }
                break;
        }

        // leverage any navigation facets we have
        writer.write("\n ");
        if (enabled) {
            writer.write("<a " + getAnchorAttrs(context, clientId,
                                                navActionType) + ">");
        }

        facet = getFacet(facetName);
        // render the facet pertaining to this widget type in the NORTH
        // and WEST cases.
        if (facet != null) {
            // If we're rendering a "go to the Nth page" link
            if (isPageNumber) {
                // See if the user specified an orientation
                String facetO = (String) getAttributes().get(
                    FACET_MARKUP_ORIENTATION_ATTR);
                if (facet != null) {
                    facetOrientation = facetO;
                    // verify that the orientation is valid
                    if (!(facetOrientation.equalsIgnoreCase(NORTH) ||
                        facetOrientation.equalsIgnoreCase(SOUTH) ||
                        facetOrientation.equalsIgnoreCase(EAST) ||
                        facetOrientation.equalsIgnoreCase(WEST))) {
                        facetOrientation = NORTH;
                    }
                }
            }

            // output the facet as specified in facetOrientation
            if (facetOrientation.equalsIgnoreCase(NORTH) ||
                facetOrientation.equalsIgnoreCase(EAST)) {
                facet.encodeBegin(context);
                if (facet.getRendersChildren()) {
                    facet.encodeChildren(context);
                }
                facet.encodeEnd(context);
            }
            // The difference between NORTH and EAST is that NORTH
            // requires a <br>.
            if (facetOrientation.equalsIgnoreCase(NORTH)) {
                writer.startElement("br", null); // PENDING(craigmcc)
                writer.endElement("br");
            }
        }

        // if we have a facet, only output the link text if
        // navActionType is number
        if (null != facet) {
            if (navActionType != ACTION_NEXT &&
                navActionType != ACTION_PREVIOUS) {
                writer.write(linkText);
            }
        } else {
            writer.write(linkText);
        }

        // output the facet in the EAST and SOUTH cases
        if (null != facet) {
            if (facetOrientation.equalsIgnoreCase(SOUTH)) {
                writer.startElement("br", null); // PENDING(craigmcc)
                writer.endElement("br");
            }
            // The difference between SOUTH and WEST is that SOUTH
            // requires a <br>.
            if (facetOrientation.equalsIgnoreCase(SOUTH) ||
                facetOrientation.equalsIgnoreCase(WEST)) {
                facet.encodeBegin(context);
                if (facet.getRendersChildren()) {
                    facet.encodeChildren(context);
                }
                facet.encodeEnd(context);
            }
        }

        if (enabled) {
            writer.write("</a>");
        }

    }


    /**
     * <p>Build and return the string consisting of the attibutes for a
     * result set navigation link anchor.</p>
     *
     * @param context  the FacesContext
     * @param clientId the clientId of the enclosing UIComponent
     * @param action   the value for the rhs of the =
     *
     * @return a String suitable for setting as the value of a navigation
     *         href.
     */
    private String getAnchorAttrs(FacesContext context, String clientId,
                                  int action) {
        int currentPage = 1;
        int formNumber = getFormNumber(context);
        Integer curPage = (Integer) getAttributes().get("currentPage");
        if (curPage != null) {
            currentPage = curPage.intValue();
        }
        String result =
            "href=\"#\" " +
            "onmousedown=\"" +
            "document.forms[" + formNumber + "]['" + clientId +
            "_action'].value='" +
            action +
            "'; " +
            "document.forms[" + formNumber + "]['" + clientId +
            "_curPage'].value='" +
            currentPage +
            "'; " +
            "document.forms[" + formNumber + "].submit()\"";

        return result;
    }


    private String getHiddenFields(String clientId) {
        String result =
            "<input type=\"hidden\" name=\"" + clientId + "_action\"/>\n" +
            "<input type=\"hidden\" name=\"" + clientId + "_curPage\"/>";

        return result;
    }


    // PENDING: avoid doing this each time called.  Perhaps
    // store in our own attr?
    protected UIForm getForm(FacesContext context) {
        UIComponent parent = this.getParent();
        while (parent != null) {
            if (parent instanceof UIForm) {
                break;
            }
            parent = parent.getParent();
        }
        return (UIForm) parent;
    }


    protected int getFormNumber(FacesContext context) {
        Map requestMap = context.getExternalContext().getRequestMap();
        int numForms = 0;
        Integer formsInt = null;
        // find out the current number of forms in the page.
        if (null != (formsInt = (Integer)
            requestMap.get(FORM_NUMBER_ATTR))) {
            numForms = formsInt.intValue();
// since the form index in the document starts from 0.
            numForms--;
        }
        return numForms;
    }


    /**
     * Returns the total number of pages in the result set based on
     * <code>rows</code> and <code>rowCount</code> of <code>UIData</code>
     * component that this scroller is associated with.
     * For the purposes of this demo, we are assuming the <code>UIData</code> to
     * be child of <code>UIForm</code> component and not nested inside a custom
     * NamingContainer.
     */
    protected int getTotalPages(FacesContext context) {
        String forValue = (String) getAttributes().get("for");
        UIData uiData = (UIData) getForm(context).findComponent(forValue);
        if (uiData == null) {
            return 0;
        }
        int rowsPerPage = uiData.getRows();
        int totalRows = 0;
        int result = 0;
        totalRows = uiData.getRowCount();
        
        if (rowsPerPage > 0){
        result = totalRows / rowsPerPage;
        if (0 != (totalRows % rowsPerPage)) {
            result++;
        }
        } else
        result = 1;
        return result;
    }


    /**
     * Returns the number of rows to display by looking up the
     * <code>UIData</code> component that this scroller is associated with.
     * For the purposes of this demo, we are assuming the <code>UIData</code> to
     * be child of <code>UIForm</code> component and not nested inside a custom
     * NamingContainer.
     */
    protected int getRowsPerPage(FacesContext context) {
        String forValue = (String) getAttributes().get("for");
        UIData uiData = (UIData) getForm(context).findComponent(forValue);
        if (uiData == null) {
            return 0;
        }
        return uiData.getRows();
    }
    
    
    
public static MethodBinding createConstantMethodBinding(String outcome) {
    return new ConstantMethodBinding(outcome);
    }    
    
}