Java tutorial
/* * Copyright (C) 2012 Google Inc. * * 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.google.api.explorer.client.embedded; import com.google.api.explorer.client.Resources; import com.google.api.explorer.client.Resources.Css; import com.google.api.explorer.client.base.ApiMethod; import com.google.api.explorer.client.base.ApiService; import com.google.api.explorer.client.base.Schema; import com.google.api.explorer.client.parameter.schema.SchemaForm; import com.google.api.explorer.client.widgets.DescendantFocusPanel; import com.google.api.explorer.client.widgets.FocusInHandler; import com.google.api.explorer.client.widgets.FocusOutHandler; import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Strings; import com.google.gwt.core.client.GWT; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.event.dom.client.FocusEvent; import com.google.gwt.event.dom.client.FocusHandler; import com.google.gwt.event.dom.client.KeyPressEvent; import com.google.gwt.event.dom.client.KeyPressHandler; import com.google.gwt.event.dom.client.KeyUpEvent; import com.google.gwt.event.dom.client.KeyUpHandler; import com.google.gwt.event.logical.shared.ValueChangeEvent; import com.google.gwt.event.logical.shared.ValueChangeHandler; import com.google.gwt.json.client.JSONException; import com.google.gwt.json.client.JSONParser; import com.google.gwt.resources.client.CssResource; import com.google.gwt.uibinder.client.UiBinder; import com.google.gwt.uibinder.client.UiField; import com.google.gwt.uibinder.client.UiHandler; import com.google.gwt.user.client.Event; import com.google.gwt.user.client.ui.Composite; import com.google.gwt.user.client.ui.Label; import com.google.gwt.user.client.ui.PopupPanel; import com.google.gwt.user.client.ui.PopupPanel.PositionCallback; import com.google.gwt.user.client.ui.PushButton; import com.google.gwt.user.client.ui.TextArea; import com.google.gwt.user.client.ui.Widget; /** * Form which shows a request body in an editor that can be used in both structured and freeform * mode, with special styling to collapse the editor when it doesn't have focus. * */ public class RequestBodyForm extends Composite { private static Css globalStyle = Resources.INSTANCE.style(); @VisibleForTesting enum BodyEditor { SCHEMA, FREEFORM, } interface RequestBodyFormUiBinder extends UiBinder<Widget, RequestBodyForm> { } interface RequestBodyFormStyle extends CssResource { String hiddenControls(); } private BodyEditor selectedEditor; @UiField public DescendantFocusPanel requestPanel; @UiField(provided = true) SchemaForm schemaForm; @UiField TextArea requestBody; @UiField Label editorSwitchError; @UiField RequestBodyFormStyle style; @UiField PushButton switchEditorMenu; @UiField PopupPanel menuPopup; @UiField PushButton showStructured; @UiField PushButton showFreeform; @UiHandler("switchEditorMenu") void discloseSwitchEditorMenu(ClickEvent event) { menuPopup.setPopupPositionAndShow(new PositionCallback() { @Override public void setPosition(int offsetWidth, int offsetHeight) { int left = switchEditorMenu.getAbsoluteLeft() + switchEditorMenu.getOffsetWidth() - offsetWidth; int top = switchEditorMenu.getAbsoluteTop() + switchEditorMenu.getOffsetHeight(); menuPopup.setPopupPosition(left, top); } }); } @UiHandler("showStructured") void selectStructuredEditor(ClickEvent event) { showEditor(BodyEditor.SCHEMA, /* Focus the editor after switching. */ true); menuPopup.hide(); } @UiHandler("showFreeform") void selectFreeformEditor(ClickEvent event) { showEditor(BodyEditor.FREEFORM, /* Focus the editor after switching. */ true); menuPopup.hide(); } /** * Create an empty request body form. */ public RequestBodyForm() { schemaForm = new SchemaForm(); initWidget(((RequestBodyFormUiBinder) GWT.create(RequestBodyFormUiBinder.class)).createAndBindUi(this)); requestPanel.addFocusInHandler(new FocusInHandler() { @Override public void onFocusIn(Event event) { // Fade in the style for the controls. requestPanel.removeStyleName(style.hiddenControls()); } }); requestPanel.addFocusOutHandler(new FocusOutHandler() { @Override public void onFocusOut(Event event) { // Fade out the style for the controls requestPanel.addStyleName(style.hiddenControls()); } }); setupEditorDataBinding(); // Remove the popup from the flow. menuPopup.show(); menuPopup.hide(); } /** * Bind the free form and schema based editors together so that when the user switches the data is * moved between editors. */ private void setupEditorDataBinding() { // Add a handler to clear body error message when the user intends to edit // the text. requestBody.addFocusHandler(new FocusHandler() { @Override public void onFocus(FocusEvent event) { editorSwitchError.setVisible(false); } }); requestBody.addValueChangeHandler(new ValueChangeHandler<String>() { @Override public void onValueChange(ValueChangeEvent<String> event) { resizeTextArea(); } }); requestBody.addKeyPressHandler(new KeyPressHandler() { @Override public void onKeyPress(KeyPressEvent event) { resizeTextArea(); } }); requestBody.addKeyUpHandler(new KeyUpHandler() { @Override public void onKeyUp(KeyUpEvent event) { resizeTextArea(); } }); } /** * Returns the text associated with the contents of the editor. */ public String getRequestBodyText() { return selectedEditor == BodyEditor.SCHEMA ? schemaForm.getStringValue() : requestBody.getText(); } /** * Sets the text of the currently selected editor to the value provided. * * @param value Json or free-form text that should be used to populate the form. */ public void setRequestBodyText(String value) { if (selectedEditor == BodyEditor.SCHEMA) { try { schemaForm.setJSONValue(JSONParser.parseStrict(value)); } catch (Exception e) { showEditor(BodyEditor.FREEFORM, /* Do not focus on this content fill. */ false); } } // This may have been the original selection, or it may have been switched to by a json parsing // error or an error when assigning the json to the schema editor. if (selectedEditor == BodyEditor.FREEFORM) { requestBody.setText(value); } } /** * Initialize the body editors based on the schema provided, starting with an * empty request. * * @param service Service which is used to find schemas. * @param method Method for which this form is being displayed. * @param requestSchema Schema for which to enable the editor of {@code null} * if none. * @param initialText Initial text which should populate the editor. */ public void setContent(ApiService service, ApiMethod method, Schema requestSchema, String initialText) { selectedEditor = null; BodyEditor editorToShow; if (requestSchema != null) { editorToShow = BodyEditor.SCHEMA; schemaForm.setSchema(service, method, requestSchema); } else { editorToShow = BodyEditor.FREEFORM; } showEditor(editorToShow, /* Do not focus on the content event. */ false); String textToShow = Strings.emptyToNull(initialText) == null ? "{}" : initialText; setRequestBodyText(textToShow); } private void resizeTextArea() { int rows = requestBody.getVisibleLines(); while (rows > 1) { requestBody.setVisibleLines(--rows); } while (requestBody.getElement().getScrollHeight() > requestBody.getElement().getClientHeight()) { requestBody.setVisibleLines(requestBody.getVisibleLines() + 1); } } /** * When the user switches tabs, the data is persistent. */ @VisibleForTesting void showEditor(BodyEditor editorType, boolean isFocused) { String text = getRequestBodyText(); switch (editorType) { case SCHEMA: // About to switch to guided view if (selectedEditor != BodyEditor.SCHEMA) { try { // If the user cleared the text, use an empty object if (text.isEmpty()) { text = "{}"; } schemaForm.setJSONValue(JSONParser.parseStrict(text)); schemaForm.setVisible(true); requestBody.setVisible(false); selectedEditor = BodyEditor.SCHEMA; showStructured.addStyleName(globalStyle.checked()); showFreeform.removeStyleName(globalStyle.checked()); requestPanel.setFocus(isFocused); } catch (JSONException e) { // If there was an error parsing the JSON abort the switch and show the cause message to // the user. editorSwitchError.setVisible(true); editorSwitchError.setText(e.getMessage()); } } break; case FREEFORM: // About to switch to free form view schemaForm.setVisible(false); requestBody.setVisible(true); requestBody.setText(text); resizeTextArea(); requestBody.setFocus(isFocused); selectedEditor = BodyEditor.FREEFORM; showStructured.removeStyleName(globalStyle.checked()); showFreeform.addStyleName(globalStyle.checked()); break; } } }