make min/max/restore quadrant controls fully accessible

- the controls to the right of tabs for minimizing, maximizing, and restoring each quadrant can now be operated by screen reader and/or keyboard, and report distinctive names indicating both which quadrant they are in, and their current state (min/max/restore)
- also gave each a unique, stable elementId

src/gwt/src/org/rstudio/core/client/ElementIds.java

@@ -442,4 +442,10 @@ public String toString()
    public final static String RSC_ACCOUNT_LIST = "rsc_account_list";
    public static String getRscAccountList() { return getElementId(RSC_ACCOUNT_LIST); }
    public final static String RSC_FILES_LIST_LABEL = "rsc_files_list_label";
+
+   // WindowFrameButton (combined with unique suffix for each quadrant
+   public final static String FRAME_MIN_BTN = "frame_min_btn";
+   public final static String FRAME_MAX_BTN = "frame_max_btn";
+   public final static String MIN_FRAME_MIN_BTN = "min_frame_min_btn";
+   public final static String MIN_FRAME_MAX_BTN = "min_frame_max_btn";
 }

src/gwt/src/org/rstudio/core/client/layout/LogicalWindow.java

@@ -1,7 +1,7 @@
 /*
  * LogicalWindow.java
  *
- * Copyright (C) 2009-12 by RStudio, Inc.
+ * Copyright (C) 2009-20 by RStudio, Inc.
  *
  * Unless you have received this program directly from RStudio pursuant
  * to the terms of a commercial license agreement with RStudio, then
@@ -104,16 +104,8 @@ public void onWindowStateChange(WindowStateChangeEvent event)
 
    public void transitionToState(WindowState newState)
    {
-      if (newState == MAXIMIZE)
-         normal_.addStyleDependentName("maximized");
-      else
-         normal_.removeStyleDependentName("maximized");
-
-      if (newState == EXCLUSIVE)
-         normal_.addStyleDependentName("exclusive");
-      else
-         normal_.removeStyleDependentName("exclusive");
-
+      normal_.setMaximizedDependentState(newState);
+      normal_.setExclusiveDependentState(newState);
       state_ = newState;
 
       if (getActiveWidget() == normal_)

src/gwt/src/org/rstudio/core/client/theme/MinimizedModuleTabLayoutPanel.java

@@ -1,7 +1,7 @@
 /*
  * MinimizedModuleTabLayoutPanel.java
  *
- * Copyright (C) 2009-19 by RStudio, Inc.
+ * Copyright (C) 2009-20 by RStudio, Inc.
  *
  * Unless you have received this program directly from RStudio pursuant
  * to the terms of a commercial license agreement with RStudio, then
@@ -30,9 +30,9 @@ public class MinimizedModuleTabLayoutPanel
       extends MinimizedWindowFrame
    implements HasSelectionHandlers<Integer>
 {
-   public MinimizedModuleTabLayoutPanel()
+   public MinimizedModuleTabLayoutPanel(String accessibleName)
    {
-      super(null, new HorizontalPanel());
+      super(null, accessibleName, new HorizontalPanel());
       addStyleName(ThemeResources.INSTANCE.themeStyles().moduleTabPanel());
       addStyleName(ThemeResources.INSTANCE.themeStyles().minimized());
    }

src/gwt/src/org/rstudio/core/client/theme/MinimizedWindowFrame.java

@@ -1,7 +1,7 @@
 /*
  * MinimizedWindowFrame.java
  *
- * Copyright (C) 2009-12 by RStudio, Inc.
+ * Copyright (C) 2009-20 by RStudio, Inc.
  *
  * Unless you have received this program directly from RStudio pursuant
  * to the terms of a commercial license agreement with RStudio, then
@@ -19,6 +19,7 @@
 import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.user.client.ui.*;
+import org.rstudio.core.client.ElementIds;
 import org.rstudio.core.client.events.HasWindowStateChangeHandlers;
 import org.rstudio.core.client.events.WindowStateChangeEvent;
 import org.rstudio.core.client.events.WindowStateChangeHandler;
@@ -43,12 +44,12 @@ public HandlerRegistration addClickHandler(ClickHandler handler)
       }
    }
 
-   public MinimizedWindowFrame(String title)
+   public MinimizedWindowFrame(String title, String accessibleName)
    {
-      this(title, null);
+      this(title, accessibleName, null);
    }
 
-   public MinimizedWindowFrame(String title, Widget extraWidget)
+   public MinimizedWindowFrame(String title, String accessibleName, Widget extraWidget)
    {
       ThemeStyles themeStyles = ThemeResources.INSTANCE.themeStyles();
 
@@ -87,29 +88,21 @@ public MinimizedWindowFrame(String title, Widget extraWidget)
          inner.setCellWidth(extraWidget, "100%");
       }
 
-      HTML minimize = createDiv(themeStyles.minimize() + " " +
-                                ThemeStyles.INSTANCE.handCursor());
-      minimize.addClickHandler(new ClickHandler()
+      WindowFrameButton minimize = new WindowFrameButton(accessibleName, WindowState.NORMAL);
+      minimize.setElementId(ElementIds.MIN_FRAME_MIN_BTN + "_" + ElementIds.idSafeString(accessibleName));
+      minimize.setStylePrimaryName(themeStyles.minimize());
+      minimize.setClickHandler(() ->
       {
-         public void onClick(ClickEvent event)
-         {
-            event.preventDefault();
-            event.stopPropagation();
-            fireEvent(new WindowStateChangeEvent(WindowState.MINIMIZE));
-         }
+         fireEvent(new WindowStateChangeEvent(WindowState.MINIMIZE));
       });
       inner.add(minimize);
 
-      HTML maximize = createDiv(themeStyles.maximize() + " " + 
-                                themeStyles.handCursor());
-      maximize.addClickHandler(new ClickHandler()
+      WindowFrameButton maximize = new WindowFrameButton(accessibleName, WindowState.MAXIMIZE);
+      maximize.setElementId(ElementIds.MIN_FRAME_MAX_BTN + "_" + ElementIds.idSafeString(accessibleName));
+      maximize.setStylePrimaryName(themeStyles.maximize());
+      maximize.setClickHandler(() ->
       {
-         public void onClick(ClickEvent event)
-         {
-            event.preventDefault();
-            event.stopPropagation();
-            fireEvent(new WindowStateChangeEvent(WindowState.MAXIMIZE));
-         }
+         fireEvent(new WindowStateChangeEvent(WindowState.MAXIMIZE));
       });
       inner.add(maximize);
 

src/gwt/src/org/rstudio/core/client/theme/PrimaryWindowFrame.java

@@ -1,7 +1,7 @@
 /*
  * PrimaryWindowFrame.java
  *
- * Copyright (C) 2009-12 by RStudio, Inc.
+ * Copyright (C) 2009-20 by RStudio, Inc.
  *
  * Unless you have received this program directly from RStudio pursuant
  * to the terms of a commercial license agreement with RStudio, then
@@ -45,6 +45,7 @@ public HandlerRegistration addMouseDownHandler(MouseDownHandler handler)
    public PrimaryWindowFrame(String title,
                              Widget mainWidget)
    {
+      super(title);
       ThemeStyles styles = ThemeResources.INSTANCE.themeStyles();
 
       panel_ = new ClickFlowPanel();

src/gwt/src/org/rstudio/core/client/theme/WindowFrame.java

@@ -1,7 +1,7 @@
 /*
  * WindowFrame.java
  *
- * Copyright (C) 2009-12 by RStudio, Inc.
+ * Copyright (C) 2009-20 by RStudio, Inc.
  *
  * Unless you have received this program directly from RStudio pursuant
  * to the terms of a commercial license agreement with RStudio, then
@@ -17,14 +17,13 @@
 import com.google.gwt.dom.client.Style;
 import com.google.gwt.dom.client.Style.Float;
 import com.google.gwt.dom.client.Style.Unit;
-import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.user.client.ui.*;
 import com.google.inject.Inject;
 
 import java.util.HashMap;
 
+import org.rstudio.core.client.ElementIds;
 import org.rstudio.core.client.events.*;
 import org.rstudio.core.client.layout.RequiresVisibilityChanged;
 import org.rstudio.core.client.layout.WindowState;
@@ -42,13 +41,13 @@ public class WindowFrame extends Composite
               EnsureVisibleHandler,
               EnsureHeightHandler
 {  
-   public WindowFrame(Widget mainWidget)
+   public WindowFrame(Widget mainWidget, String name)
    {
-      this();
+      this(name);
       setMainWidget(mainWidget);
    }
 
-   public WindowFrame()
+   public WindowFrame(String name)
    {
       RStudioGinjector.INSTANCE.injectMembers(this);
 
@@ -60,27 +59,15 @@ public WindowFrame()
       borderPositioner_ = new SimplePanel();
       borderPositioner_.add(border_);
 
-      HTML maximize = new HTML();
-      maximize.setStylePrimaryName(styles.maximize());
-      maximize.addStyleName(ThemeStyles.INSTANCE.handCursor());
-      maximize.addClickHandler(new ClickHandler()
-      {
-         public void onClick(ClickEvent event)
-         {
-            maximize();
-         }
-      });
+      maximizeButton_ = new WindowFrameButton(name, WindowState.MAXIMIZE);
+      maximizeButton_.setElementId(ElementIds.FRAME_MAX_BTN + "_" + ElementIds.idSafeString(name));
+      maximizeButton_.setStylePrimaryName(styles.maximize());
+      maximizeButton_.setClickHandler(() -> maximize());
 
-      HTML minimize = new HTML();
-      minimize.setStylePrimaryName(styles.minimize());
-      minimize.addStyleName(ThemeStyles.INSTANCE.handCursor());
-      minimize.addClickHandler(new ClickHandler()
-      {
-         public void onClick(ClickEvent event)
-         {
-            minimize();
-         }
-      });
+      minimizeButton_ = new WindowFrameButton(name, WindowState.MINIMIZE);
+      minimizeButton_.setElementId(ElementIds.FRAME_MIN_BTN + "_" + ElementIds.idSafeString(name));
+      minimizeButton_.setStylePrimaryName(styles.minimize());
+      minimizeButton_.setClickHandler(() -> minimize());
 
       frame_ = new LayoutPanel();
       frame_.setStylePrimaryName(styles.windowframe());
@@ -92,22 +79,22 @@ public void onClick(ClickEvent event)
       frame_.setWidgetLeftRight(borderPositioner_, 0, Style.Unit.PX,
                                                    0, Style.Unit.PX);
 
-      frame_.add(maximize);
-      frame_.setWidgetTopHeight(maximize,
+      frame_.add(minimizeButton_);
+      frame_.setWidgetTopHeight(minimizeButton_,
+            ShadowBorder.TOP_SHADOW_WIDTH + 4, Style.Unit.PX,
+            14, Style.Unit.PX);
+      frame_.setWidgetRightWidth(minimizeButton_,
+            ShadowBorder.RIGHT_SHADOW_WIDTH + 25, Style.Unit.PX,
+            14, Style.Unit.PX);
+
+      frame_.add(maximizeButton_);
+      frame_.setWidgetTopHeight(maximizeButton_,
                                 ShadowBorder.TOP_SHADOW_WIDTH + 4, Style.Unit.PX,
                                 14, Style.Unit.PX);
-      frame_.setWidgetRightWidth(maximize,
+      frame_.setWidgetRightWidth(maximizeButton_,
                                  ShadowBorder.RIGHT_SHADOW_WIDTH + 7, Style.Unit.PX,
                                  14, Style.Unit.PX);
 
-      frame_.add(minimize);
-      frame_.setWidgetTopHeight(minimize,
-                                ShadowBorder.TOP_SHADOW_WIDTH + 4, Style.Unit.PX,
-                                14, Style.Unit.PX);
-      frame_.setWidgetRightWidth(minimize,
-                                 ShadowBorder.RIGHT_SHADOW_WIDTH + 25, Style.Unit.PX,
-                                 14, Style.Unit.PX);
-
       buttonsArea_ = new FlowPanel();
       frame_.add(buttonsArea_);
 
@@ -372,9 +359,33 @@ public Widget getFillWidget()
       return fill_;
    }
 
+   public void setMaximizedDependentState(WindowState state)
+   {
+      if (state == WindowState.MAXIMIZE)
+      {
+         addStyleDependentName("maximized");
+      }
+      else
+      {
+         removeStyleDependentName("maximized");
+      }
+      maximizeButton_.setMaximized(state == WindowState.MAXIMIZE);
+   }
+
+   public void setExclusiveDependentState(WindowState state)
+   {
+      if (state == WindowState.EXCLUSIVE)
+         addStyleDependentName("exclusive");
+      else
+         removeStyleDependentName("exclusive");
+      maximizeButton_.setExclusive(state == WindowState.EXCLUSIVE);
+   }
+
    private final LayoutPanel frame_;
    private final ShadowBorder border_;
    private final SimplePanel borderPositioner_;
+   private final WindowFrameButton maximizeButton_;
+   private final WindowFrameButton minimizeButton_;
    private Widget main_;
    private Widget header_;
    private Widget fill_;