[[creating-a-simple-component-container]]
Creating a simple component container
-------------------------------------

Components in Vaadin can be roughly split into two groups, `Component`{empty}s
and `ComponentContainer`{empty}s. ComponentContainers are Components in
themselves which can also contain other components. If you are about to
implement a component that contains other components, then you'll get a
headstart by extending Vaadin's `ComponentContainer`. The biggest feature
is in tranferring the list of server side components from your component
to the client. Here's how you do it.

[[server-side]]
Server Side
^^^^^^^^^^^

To start of we implement our server side component. For this we extend
the ready made abstract implementation `AbstractComponentContainer`. This
requires us to implement `addComponent(Component)`,
`removeComponent(Component)`, `replaceComponent(Component, Component)`,
`getComponentCount` and `getComponentIterator()`.

[source,java]
....
package com.example.widgetcontainer;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import com.vaadin.ui.AbstractComponentContainer;
import com.vaadin.ui.Component;

public class WidgetContainer extends AbstractComponentContainer {

  List<Component> children = new ArrayList<Component>();

  @Override
  public void addComponent(Component c) {
    children.add(c);
    super.addComponent(c);
    markAsDirty();
  }

  @Override
  public void removeComponent(Component c) {
    children.remove(c);
    super.removeComponent(c);
    markAsDirty();
  }

  public void replaceComponent(Component oldComponent, Component newComponent) {
    int index = children.indexOf(oldComponent);
    if (index != -1) {
      children.remove(index);
      children.add(index, newComponent);
      fireComponentDetachEvent(oldComponent);
      fireComponentAttachEvent(newComponent);
      markAsDirty();
    }
  }

  public int getComponentCount() {
    return children.size();
  }

  public Iterator<Component> iterator() {
    return children.iterator();
  }
}
....

Add, remove and replace are quite straight forward. In the class we
upkeep a list of children internally, and these three methods modify
them. Add and remove have ready made methods in the super class for
notifying all event handlers that the children have changed and because
of that we should make calls to the super methods after w
/*
 * Copyright 2011 gitblit.com.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.gitblit;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.net.URL;
import java.util.Arrays;
import java.util.List;
import java.util.jar.Attributes;
import java.util.jar.Manifest;

/**
 * Constant values used by Gitblit.
 *
 * @author James Moger
 *
 */
public class Constants {

	public static final String NAME = "Gitblit";

	public static final String FULL_NAME = "Gitblit - a pure Java Git solution";

	public static final String ADMIN_ROLE = "#admin";

	public static final String FORK_ROLE = "#fork";

	public static final String CREATE_ROLE = "#create";

	public static final String NOT_FEDERATED_ROLE = "#notfederated";

	public static final String NO_ROLE = "#none";

	public static final String EXTERNAL_ACCOUNT = "#externalAccount";

	public static final String PROPERTIES_FILE = "gitblit.properties";

	public static final String DEFAULT_USER_REPOSITORY_PREFIX = "~";

	public static final String R_PATH = "/r/";

	public static final String GIT_PATH = "/git/";

	public static final String ZIP_PATH = "/zip/";

	public static final String SYNDICATION_PATH = "/feed/";

	public static final String FEDERATION_PATH = "/federation/";

	public static final String RPC_PATH = "/rpc/";

	public static final String PAGES = "/pages/";

	public static final String SPARKLESHARE_INVITE_PATH = "/sparkleshare/";

	public static final String RAW_PATH = "/raw/";

	public static final String PT_PATH = "/pt";

	public static final String BRANCH_GRAPH_PATH = "/graph/";

	public static final String BORDER = "*****************************************************************";

	public static final String BORDER2 = "#################################################################";

	public static final String FEDERATION_USER = "$gitblit";

	public static final String PROPOSAL_EXT = ".json";

	public static final String ENCODING = "UTF-8";

	public static final int LEN_SHORTLOG = 78;

	public static final int LEN_SHORTLOG_REFS = 60;

	public static final String DEFAULT_BRANCH = "default";

	public static final String CONFIG_GITBLIT = "gitblit";

	public static final String CONFIG_CUSTOM_FIELDS = "customFields";

	public static final String ISO8601 = "yyyy-MM-dd'T'HH:mm:ssZ";

	public static final String baseFolder = "baseFolder";

	public static final String baseFolder$ = "${" + baseFolder + "}";

	public static final String contextFolder$ = "${contextFolder}";

	public static final String HEAD = "HEAD";

	public static final String R_META = "refs/meta/";

	public static final String R_HEADS = "refs/heads/";

	public static final String R_NOTES = "refs/notes/";

	public static final String R_CHANGES = "refs/changes/";

	public static final String R_PULL = "refs/pull/";

	public static final String R_TAGS = "refs/tags/";

	public static final String R_REMOTES = "refs/remotes/";

	public static final String R_FOR = "refs/for/";

	public static final String R_TICKET = "refs/heads/ticket/";

	public static final String R_TICKETS_PATCHSETS = "refs/tickets/";

	public static final String R_MASTER = "refs/heads/master";

	public static final String MASTER = "master";

	public static final String R_DEVELOP = "refs/heads/develop";

	public static final String DEVELOP = "develop";

	public static String getVersion() {
		String v = Constants.class.getPackage().getImplementationVersion();
		if (v == null) {
			return "0.0.0-SNAPSHOT";
		}
		return v;
	}

	public static String getGitBlitVersion() {
		return NAME + " v" + getVersion();
	}

	public static String getBuildDate() {
		return getManifestValue("build-date", "PENDING");
	}

	public static String getASCIIArt() {
		StringBuilder sb = new StringBuilder();
		sb.append("  _____  _  _    _      _  _  _").append('\n');
		sb.append(" |  __ \\(_)| |  | |    | |(_)| |").append('\n');
		sb.append(" | |  \\/ _ | |_ | |__  | | _ | |_").append('\n');
		sb.append(" | | __ | || __|| '_ \\ | || || __|").append("  ").append("http://gitblit.com").append('\n');
		sb.append(" | |_\\ \\| || |_ | |_) || || || |_").append("   ").append("@gitblit").append('\n');
		sb.append("  \\____/|_| \\__||_.__/ |_||_| \\__|").append("  ").append(Constants.getVersion()).append('\n');
		return sb.toString();
	}

	private static String getManifestValue(String attrib, String defaultValue) {
		Class<?> clazz = Constants.class;
		String className = clazz.getSimpleName() + ".class";
		String classPath = clazz.getResource(className).toString();
		if (!classPath.startsWith("jar")) {
			// Class not from JAR
			return defaultValue;
		}
		try {
			String manifestPath = classPath.substring(0, classPath.lastIndexOf("!") + 1) + "/META-INF/MANIFEST.MF";
			Manifest manifest = new Manifest(new URL(manifestPath).openStream());
			Attributes attr = manifest.getMainAttributes();
			String value = attr.getValue(attrib);
			return value;
		} catch (Exception e) {
		}
		return defaultValue;
	}

	/**
	 * Enumeration representing the four access restriction levels.
	 */
	public static enum AccessRestrictionType {
		NONE, PUSH, CLONE, VIEW;

		private static final AccessRestrictionType [] AUTH_TYPES = { PUSH, CLONE, VIEW };

		public static AccessRestrictionType fromName(String name) {
			for (AccessRestrictionType type : values()) {
				if (type.name().equalsIgnoreCase(name)) {
					return type;
				}
			}
			return NONE;
		}

		public static List<AccessRestrictionType> choices(boolean allowAnonymousPush) {
			if (allowAnonymousPush) {
				return Arrays.asList(values());
			}
			return Arrays.asList(AUTH_TYPES);
		}

		public boolean exceeds(AccessRestrictionType type) {
			return this.ordinal() > type.ordinal();
		}

		public boolean atLeast(AccessRestrictionType type) {
			return this.ordinal() >= type.ordinal();
		}

		@Override
		public String toString() {
			return name();
		}

		public boolean isValidPermission(AccessPermission permission) {
			switch (this) {
			case VIEW:
				// VIEW restriction
				// all access permissions are valid
				return true;
			case CLONE:
				// CLONE restriction
				// only CLONE or greater access permissions are valid
				return permission.atLeast(AccessPermission.CLONE);
			case PUSH:
				// PUSH restriction
				// only PUSH or greater access permissions are valid
				return permission.atLeast(AccessPermission.PUSH);
			case NONE:
				// NO access restriction
				// all access permissions are invalid
				return false;
			}
			return false;
		}
	}

	/**
	 * Enumeration representing the types of authorization control for an
	 * access restricted resource.
	 */
	public static enum AuthorizationControl {
		AUTHENTICATED, NAMED;

		public static AuthorizationControl fromName(String name) {
			for (AuthorizationControl type : values()) {
				if (type.name().equalsIgnoreCase(name)) {
					return type;
				}
			}
			return NAMED;
		}

		@Override
		public String toString() {
			return name();
		}
	}


	/**
	 * Enumeration representing the types of federation tokens.
	 */
	public static enum FederationToken {
		ALL, USERS_AND_REPOSITORIES, REPOSITORIES;

		public static FederationToken fromName(String name) {
			for (FederationToken type : values()) {
				if (type.name().equalsIgnoreCase(name)) {
					return type;
				}
			}
			return REPOSITORIES;
		}

		@Override
		public String toString() {
			return name();
		}
	}

	/**
	 * Enumeration representing the types of federation requests.
	 */
	public static enum FederationRequest {
		POKE, PROPOSAL, PULL_REPOSITORIES, PULL_USERS, PULL_TEAMS, PULL_SETTINGS, PULL_SCRIPTS, STATUS;

		public static FederationRequest fromName(String name) {
			for (FederationRequest type : values()) {
				if (type.name().equalsIgnoreCase(name)) {
					return type;
				}
			}
			return PULL_REPOSITORIES;
		}

		@Override
		public String toString() {
			return name();
		}
	}

	/**
	 * Enumeration representing the statii of federation requests.
	 */
	public static enum FederationPullStatus {
		PENDING, FAILED, SKIPPED, PULLED, MIRRORED, NOCHANGE, EXCLUDED;

		public static FederationPullStatus fromName(String name) {
			for (FederationPullStatus type : values()) {
				if (type.name().equalsIgnoreCase(name)) {
					return type;
				}
			}
			return PENDING;
		}

		@Override
		public String toString() {
			return name();
		}
	}

	/**
	 * Enumeration representing the federation types.
	 */
	public static enum FederationStrategy {
		EXCLUDE, FEDERATE_THIS, FEDERATE_ORIGIN;

		public static FederationStrategy fromName(String name) {
			for (FederationStrategy type : values()) {
				if (type.name().equalsIgnoreCase(name)) {
					return type;
				}
			}
			return FEDERATE_THIS;
		}

		public boolean exceeds(FederationStrategy type) {
			return this.ordinal() > type.ordinal();
		}

		public boolean atLeast(FederationStrategy type) {
			return this.ordinal() >= type.ordinal();
		}

		@Override
		public String toString() {
			return name();
		}
	}

	/**
	 * Enumeration representing the possible results of federation proposal
	 * requests.
	 */
	public static enum FederationProposalResult {
		ERROR, FEDERATION_DISABLED, MISSING_DATA, NO_PROPOSALS, NO_POKE, ACCEPTED;

		@Override
		public String toString() {
			return name();
		}
	}

	/**
	 * Enumeration representing the possible remote procedure call requests from
	 * a client.
	 */
	public static enum RpcRequest {
		// Order is important here.  anything after LIST_SETTINGS requires
		// administrator privileges and web.allowRpcManagement.
		CLEAR_REPOSITORY_CACHE, REINDEX_TICKETS, GET_PROTOCOL, LIST_REPOSITORIES, LIST_BRANCHES, GET_USER,
		FORK_REPOSITORY, LIST_SETTINGS,
		CREATE_REPOSITORY, EDIT_REPOSITORY, DELETE_REPOSITORY,
		LIST_USERS, CREATE_USER, EDIT_USER, DELETE_USER,
		LIST_TEAMS, CREATE_TEAM, EDIT_TEAM, DELETE_TEAM,
		LIST_REPOSITORY_MEMBERS, SET_REPOSITORY_MEMBERS, LIST_REPOSITORY_TEAMS, SET_REPOSITORY_TEAMS,
		LIST_REPOSITORY_MEMBER_PERMISSIONS, SET_REPOSITORY_MEMBER_PERMISSIONS, LIST_REPOSITORY_TEAM_PERMISSIONS, SET_REPOSITORY_TEAM_PERMISSIONS,
		LIST_FEDERATION_REGISTRATIONS, LIST_FEDERATION_RESULTS, LIST_FEDERATION_PROPOSALS, LIST_FEDERATION_SETS,
		EDIT_SETTINGS, LIST_STATUS;

		public static RpcRequest fromName(String name) {
			for (RpcRequest type : values()) {
				if (type.name().equalsIgnoreCase(name)) {
					return type;
				}
			}
			return null;
		}

		public boolean exceeds(RpcRequest type) {
			return this.ordinal() > type.ordinal();
		}

		@Override
		public String toString() {
			return name();
		}
	}

	/**
	 * Enumeration of the search types.
	 */
	public static enum SearchType {
		AUTHOR, COMMITTER, COMMIT;

		public static SearchType forName(String name) {
			for (SearchType type : values()) {
				if (type.name().equalsIgnoreCase(name)) {
					return type;
				}
			}
			return COMMIT;
		}

		@Override
		public String toString() {
			return name().toLowerCase();
		}
	}

	/**
	 * Enumeration of the feed content object types.
	 */
	public static enum FeedObjectType {
		COMMIT, TAG;

		public static FeedObjectType forName(String name) {
			for (FeedObjectType type : values()) {
				if (type.name().equalsIgnoreCase(name)) {
					return type;
				}
			}
			return COMMIT;
		}

		@Override
		public String toString() {
			return name().toLowerCase();
		}
	}

	/**
	 * The types of objects that can be indexed and queried.
	 */
	public static enum SearchObjectType {
		commit, blob;

		public static SearchObjectType fromName(String name) {
			for (SearchObjectType value : values()) {
				if (value.name().equals(name)) {
					return value;
				}
			}
			return null;
		}
	}

	/**
	 * The access permissions available for a repository.
	 */
	public static enum AccessPermission {
		NONE("N"), EXCLUDE("X"), VIEW("V"), CLONE("R"), PUSH("RW"), CREATE("RWC"), DELETE("RWD"), REWIND("RW+"), OWNER("RW+");

		public static final AccessPermission [] NEWPERMISSIONS = { EXCLUDE, VIEW, CLONE, PUSH, CREATE, DELETE, REWIND };

		public static final AccessPermission [] SSHPERMISSIONS = { VIEW, CLONE, PUSH };

		public static AccessPermission LEGACY = REWIND;

		public final String code;

		private AccessPermission(String code) {
			this.code = code;
		}

		public boolean atMost(AccessPermission perm) {
			return ordinal() <= perm.ordinal();
		}

		public boolean atLeast(AccessPermission perm) {
			return ordinal() >= perm.ordinal();
		}

		public boolean exceeds(AccessPermission perm) {
			return ordinal() > perm.ordinal();
		}

		public String asRole(String repository) {
			return code + ":" + repository;
		}

		@Override
		public String toString() {
			return code;
		}

		public static AccessPermission permissionFromRole(String role) {
			String [] fields = role.split(":", 2);
			if (fields.length == 1) {
				// legacy/undefined assume full permissions
				return AccessPermission.LEGACY;
			} else {
				// code:repository
				return AccessPermission.fromCode(fields[0]);
			}
		}

		public static String repositoryFromRole(String role) {
			String [] fields = role.split(":", 2);
			if (fields.length == 1) {
				// legacy/undefined assume full permissions
				return role;
			} else {
				// code:repository
				return fields[1];
			}
		}

		public static AccessPermission fromCode(String code) {
			for (AccessPermission perm : values()) {
				if (perm.code.equalsIgnoreCase(code)) {
					return perm;
				}
			}
			return AccessPermission.NONE;
		}
	}

	public static enum RegistrantType {
		REPOSITORY, USER, TEAM;
	}

	public static enum PermissionType {
		MISSING, ANONYMOUS, EXPLICIT, TEAM, REGEX, OWNER, ADMINISTRATOR;
	}

	public static enum GCStatus {
		READY, COLLECTING;

		public boolean exceeds(GCStatus s) {
			return ordinal() > s.ordinal();
		}
	}

	public static enum AuthenticationType {
		PUBLIC_KEY, CREDENTIALS, COOKIE, CERTIFICATE, CONTAINER;

		public boolean isStandard() {
			return ordinal() <= COOKIE.ordinal();
		}
	}

	public static enum AccountType {
		LOCAL, EXTERNAL, CONTAINER, LDAP, REDMINE, SALESFORCE, WINDOWS, PAM, HTPASSWD;

		public static AccountType fromString(String value) {
			for (AccountType type : AccountType.values()) {
				if (type.name().equalsIgnoreCase(value)) {
					return type;
				}
			}
			return AccountType.LOCAL;
		}

		public boolean isLocal() {
			return this == LOCAL;
		}
	}

	public static enum CommitMessageRenderer {
		PLAIN, MARKDOWN;

		public static CommitMessageRenderer fromName(String name) {
			for (CommitMessageRenderer renderer : values()) {
				if (renderer.name().equalsIgnoreCase(name)) {
					return renderer;
				}
			}
			return CommitMessageRenderer.PLAIN;
		}
	}

	public static enum Transport {
		// ordered for url advertisements, assuming equal access permissions
		SSH, HTTPS, HTTP, GIT;

		public static Transport fromString(String value) {
			for (Transport t : values()) {
				if (t.name().equalsIgnoreCase(value)) {
					return t;
				}
			}
			return null;
		}

		public static Transport fromUrl(String url) {
			int delim = url.indexOf("://");
			if (delim == -1) {
				// if no protocol is specified, SSH is assumed by git clients
				return SSH;
			}
			String scheme = url.substring(0, delim);
			return fromString(scheme);
		}
	}

	@Documented
	@Retention(RetentionPolicy.RUNTIME)
	public @interface Unused {
	}
}