Java tutorial
/* * Copyright 2011, The gwtquery team. * * 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.cgxlib.xq.client.js; /* * #%L * CGXlib * %% * Copyright (C) 2016 CGXlib (http://www.cgxlib.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. * #L% Code is originally from gwtquery, and modified by CGXlib team. */ import com.google.gwt.core.client.GWT; import com.google.gwt.core.client.JavaScriptObject; import com.google.gwt.core.client.JsArrayMixed; import com.google.gwt.core.client.JsArrayString; /** * A Lightweight JSO class to store data. */ public class JsCache extends JavaScriptObject { protected JsCache() { } public static JsCache create() { return createObject().cast(); } /** * Throw a NPE when a js is null. */ public static final <T extends JavaScriptObject> T checkNull(T js) { if (!GWT.isProdMode() && js == null) { throw new NullPointerException(); } return js; } /** * Gets an object wrapped in a js array and boxes it with the appropriate * object in the GWT world. * <p/> * It is thought to be called from other jsni code without dealing with casting issues. * <p/> * It will box the unique element in the array with a Boolean or a Double in the case * of primitive variables, otherwise it returns the object itself, or null if undefined. * <p/> * Example * <pre> * native Object myMethod() /*-{ * var myJsVar = ... ; * return @com.cgxlib.xq.client.js.JsCache::gwtBox(*)([ myJsVar ]); * }-* / * </pre> */ public static native Object gwtBox(JavaScriptObject oneElementArray) /*-{ var r = oneElementArray; if (typeof r == 'object' && r.length == 1) { var r = r[0], t = typeof r; if (t == 'boolean') return @java.lang.Boolean::valueOf(Z)(r); if (t == 'number') return @java.lang.Double::valueOf(D)(r); } return r || null; }-*/; public final native void concat(Object ary) /*-{ if (ary) this.concat(ary); }-*/; public final void copy(JsCache jso) { for (String k : jso.keys()) { put(k, jso.get(k)); } } public final void pushAll(JavaScriptObject prevElem) { checkNull(); JsCache c = prevElem.cast(); for (int i = 0, ilen = c.length(); i < ilen; i++) { put(length(), c.get(i)); } } public final native void delete(Object name) /*-{ delete this[name]; }-*/; public final void clear() { for (String k : keys()) { delete(k); } } public final native boolean exists(Object name) /*-{ return !!this[name]; }-*/; @SuppressWarnings("unchecked") public final <T> T get(Object id, Class<? extends T> clz) { Object o = get(id); if (o != null && clz != null) { if (o instanceof Double) { Double d = (Double) o; if (clz == Float.class) o = d.floatValue(); else if (clz == Integer.class) o = d.intValue(); else if (clz == Long.class) o = d.longValue(); else if (clz == Short.class) o = d.shortValue(); else if (clz == Byte.class) o = d.byteValue(); } else if (clz == Boolean.class && !(o instanceof Boolean)) { o = Boolean.valueOf(String.valueOf(o)); } else if (clz == String.class && !(o instanceof String)) { o = String.valueOf(o); } } return (T) o; } public final native <T> T get(Object id) /*-{ return @com.cgxlib.xq.client.js.JsCache::gwtBox(*)([this && this[id]]); }-*/; public final JsCache getCache(int id) { return (JsCache) get(id); } public final boolean getBoolean(Object id) { Boolean r = get(id, Boolean.class); return r == null ? false : r; } public final float getFloat(Object id) { Float r = get(id, Float.class); return r == null ? 0 : r; } public final double getDouble(Object id) { Double r = get(id, Double.class); return r == null ? 0 : r; } public final int getInt(Object id) { Integer r = get(id, Integer.class); return r == null ? 0 : r; } public final native String getString(Object id) /*-{ return this[id] == null ? null : String(this[id]); }-*/; public final native JsArrayMixed getArray(Object id) /*-{ var r = this[id]; if (Object.prototype.toString.call(r) == '[object Array]') { return r; } return null; }-*/; public final <T extends JavaScriptObject> T getJavaScriptObject(Object name) { Object o = get(name); return (o != null && o instanceof JavaScriptObject) ? ((JavaScriptObject) o).<T>cast() : null; } public final native boolean isEmpty() /*-{ for (k in this) { if (this.hasOwnProperty(k)) return false; } return true; }-*/; public final native boolean contains(Object o) /*-{ return this.indexOf(o) >= 0; }-*/; public final native void remove(Object o) /*-{ var i = this.indexOf(o); if (i >= 0) this.splice(i, 1); }-*/; public final native int indexOf(Object o) /*-{ // HtmlUnit fails when this returns 0 return this.indexOf(o); }-*/; public final native JsCache putBoolean(Object id, boolean b) /*-{ this[id] = b; return this; }-*/; public final native JsCache putNumber(Object id, double n) /*-{ this[id] = n; return this; }-*/; public final JsCache put(Object id, Object obj) { if (obj instanceof Boolean) { putBoolean(id, ((Boolean) obj).booleanValue()); } else if (obj instanceof Number) { putNumber(id, ((Number) obj).doubleValue()); } else { putObject(id, obj); } return this; } public final native JsCache putObject(Object id, Object obj) /*-{ this[id] = obj; return this; }-*/; public final native int length() /*-{ if (typeof(this.length) == 'number') return this.length; var key, ret = 0; // Chrome in DevMode injects a property to JS objects for (key in this) { if (key != "__gwt_ObjectId") ret++; } return ret; }-*/; public final int[] indexes() { checkNull(); JsArrayString a = keysImpl(); int[] ret = new int[a.length()]; for (int i = 0; i < a.length(); i++) { try { ret[i] = Integer.valueOf(a.get(i)); } catch (Exception e) { ret[i] = i; } } return ret; } public final String[] keys() { checkNull(); JsArrayString a = keysImpl(); String[] ret = new String[a.length()]; for (int i = 0; i < a.length(); i++) { ret[i] = a.get(i); } return ret; } public final Object[] elements() { String[] keys = keys(); Object[] ret = new Object[keys.length]; int i = 0; for (String s : keys) { ret[i++] = get(s); } return ret; } public final String tostring() { String ret = getClass().getName() + "{ "; for (String k : keys()) { ret += k + "=" + get(k) + " "; } return ret + "}"; } // In dev-mode a null object casted to JavascriptObject does not throw a NPE public final void checkNull() { checkNull(this); } private native JsArrayString keysImpl() /*-{ var key, keys = []; // Chrome in DevMode sets '__gwt_ObjectId' to JS objects // GWT sets '$H' when calling getHashCode (see com/google/gwt/core/client/impl/Impl.java) for (key in this) { if (this.hasOwnProperty(key) && key != '__gwt_ObjectId' && key != '$H') keys.push(String(key)); } return keys; }-*/; }