Add tooltip support to Windows tables.

This doesn't actually make use of the functionality yet, but we get a nice benefit for free: by turning this on, we automatically get "labeltips" (see comments in the code) for all elided items in tables.

BUG=43259
TEST=Hover any elided item in a table and it should display a tooltip with the full item text atop it.
Review URL: http://codereview.chromium.org/2012006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@46832 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 96 insertions, 9 deletions

diff --git a/app/table_model.h b/app/table_model.h
index b2a07a1..82bb9af 100644
--- a/app/table_model.h
+++ b/app/table_model.h
@@ -40,6 +40,13 @@ class TableModel {
   // no bitmap.
   virtual SkBitmap GetIcon(int row);
 
+  // Returns the tooltip, if any, to show for a particular row.  If there are
+  // multiple columns in the row, this will only be shown when hovering over
+  // column zero.
+  virtual std::wstring GetTooltip(int row) {
+    return std::wstring();
+  }
+
   // Returns true if the TableView has groups. Groups provide a way to visually
   // delineate the rows in a table view. When groups are enabled table view
   // shows a visual separator for each group, followed by all the rows in
diff --git a/views/controls/table/native_table_win.cc b/views/controls/table/native_table_win.cc
index a30d1bf..1b0806e 100644
--- a/views/controls/table/native_table_win.cc
+++ b/views/controls/table/native_table_win.cc
@@ -295,9 +295,48 @@ bool NativeTableWin::ProcessMessage(UINT message, WPARAM w_param,
         break;
       }
 
-      case LVN_MARQUEEBEGIN:  // We don't want the marque selection.
+      case LVN_MARQUEEBEGIN:  // We don't want the marquee selection.
         return true;
 
+      case LVN_GETINFOTIP: {
+        // This is called when the user hovers items in column zero.
+        //   * If the text in this column is not fully visible, the dwFlags
+        //     field will be set to 0, and pszText will contain the full text.
+        //     If you return without making any changes, this text will be
+        //     displayed in a "labeltip" - a bubble that's overlaid (at the
+        //     correct alignment!) on the item.  If you return with a different
+        //     pszText, it will be displayed as a tooltip if nonempty.
+        //   * Otherwise, dwFlags will be LVGIT_UNFOLDED and pszText will be
+        //     empty.  On return, if pszText is nonempty, it will be displayed
+        //     as a labeltip if dwFlags has been changed to 0 (even if it bears
+        //     no resemblance to the item text), or as a tooltip otherwise.
+        //
+        // Once the tooltip for an item has been obtained, this will not be
+        // called again until the user hovers a different item.  If after that
+        // the original item is hovered a second time, this will be called.
+        //
+        // When the user hovers items in other columns, they will be "unfolded"
+        // (displayed as labeltips) when necessary, but this function will
+        // never be called.
+        //
+        // Changing the LVS_EX_INFOTIP extended style to LVS_EX_LABELTIP will
+        // cause all of the above to be true except that this function will not
+        // be called when dwFlags would be LVGIT_UNFOLDED.  Removing it entirely
+        // will disable all of the above behavior.
+        NMLVGETINFOTIP* info_tip = reinterpret_cast<NMLVGETINFOTIP*>(hdr);
+        std::wstring tooltip = table_->model()->GetTooltip(info_tip->iItem);
+        CHECK(info_tip->cchTextMax >= 2);
+        if (tooltip.length() >= static_cast<size_t>(info_tip->cchTextMax)) {
+          // Elide the tooltip if necessary.
+          tooltip.erase(info_tip->cchTextMax - 2);  // Ellipsis + '\0'
+          const wchar_t kEllipsis = L'\x2026';
+          tooltip += kEllipsis;
+        }
+        if (!tooltip.empty())
+          wcscpy_s(info_tip->pszText, tooltip.length() + 1, tooltip.c_str());
+        return true;
+      }
+
       default:
         break;
     }
@@ -327,10 +366,11 @@ void NativeTableWin::CreateNativeControl() {
                                table_->GetWidget()->GetNativeView(),
                                NULL, NULL, NULL);
 
-  // Reduce overdraw/flicker artifacts by double buffering.  Make the selection
-  // extend across the row.
-  ListView_SetExtendedListViewStyle(hwnd,
-                                    LVS_EX_DOUBLEBUFFER | LVS_EX_FULLROWSELECT);
+  // Reduce overdraw/flicker artifacts by double buffering.  Support tooltips
+  // and display elided items completely on hover (see comments in OnNotify()
+  // under LVN_GETINFOTIP).  Make the selection extend across the row.
+  ListView_SetExtendedListViewStyle(list_view_,
+      LVS_EX_DOUBLEBUFFER | LVS_EX_INFOTIP | LVS_EX_FULLROWSELECT);
   l10n_util::AdjustUIFontForWindow(hwnd);
 
   NativeControlCreated(hwnd);
diff --git a/views/controls/table/table_view.cc b/views/controls/table/table_view.cc
index 73ea02c..c1d07d9 100644
--- a/views/controls/table/table_view.cc
+++ b/views/controls/table/table_view.cc
@@ -791,10 +791,11 @@ HWND TableView::CreateNativeControl(HWND parent_container) {
                                 0, 0, width(), height(),
                                 parent_container, NULL, NULL, NULL);
 
-  // Reduce overdraw/flicker artifacts by double buffering.  Make the selection
-  // extend across the row.
+  // Reduce overdraw/flicker artifacts by double buffering.  Support tooltips
+  // and display elided items completely on hover (see comments in OnNotify()
+  // under LVN_GETINFOTIP).  Make the selection extend across the row.
   ListView_SetExtendedListViewStyle(list_view_,
-                                    LVS_EX_DOUBLEBUFFER | LVS_EX_FULLROWSELECT);
+      LVS_EX_DOUBLEBUFFER | LVS_EX_INFOTIP | LVS_EX_FULLROWSELECT);
   l10n_util::AdjustUIFontForWindow(list_view_);
 
   // Add the columns.
@@ -1053,9 +1054,48 @@ LRESULT TableView::OnNotify(int w_param, LPNMHDR hdr) {
       break;
     }
 
-    case LVN_MARQUEEBEGIN:  // We don't want the marque selection.
+    case LVN_MARQUEEBEGIN:  // We don't want the marquee selection.
       return 1;
 
+    case LVN_GETINFOTIP: {
+      // This is called when the user hovers items in column zero.
+      //   * If the text in this column is not fully visible, the dwFlags field
+      //     will be set to 0, and pszText will contain the full text.  If you
+      //     return without making any changes, this text will be displayed in a
+      //     "labeltip" - a bubble that's overlaid (at the correct alignment!)
+      //     on the item.  If you return with a different pszText, it will be
+      //     displayed as a tooltip if nonempty.
+      //   * Otherwise, dwFlags will be LVGIT_UNFOLDED and pszText will be
+      //     empty.  On return, if pszText is nonempty, it will be displayed as
+      //     a labeltip if dwFlags has been changed to 0 (even if it bears no
+      //     resemblance to the item text), or as a tooltip otherwise.
+      //
+      // Once the tooltip for an item has been obtained, this will not be called
+      // again until the user hovers a different item.  If after that the
+      // original item is hovered a second time, this will be called.
+      //
+      // When the user hovers items in other columns, they will be "unfolded"
+      // (displayed as labeltips) when necessary, but this function will never
+      // be called.
+      //
+      // Changing the LVS_EX_INFOTIP extended style to LVS_EX_LABELTIP will
+      // cause all of the above to be true except that this function will not be
+      // called when dwFlags would be LVGIT_UNFOLDED.  Removing it entirely will
+      // disable all of the above behavior.
+      NMLVGETINFOTIP* info_tip = reinterpret_cast<NMLVGETINFOTIP*>(hdr);
+      std::wstring tooltip =
+          model_->GetTooltip(view_to_model(info_tip->iItem));
+      CHECK(info_tip->cchTextMax >= 2);
+      if (tooltip.length() >= static_cast<size_t>(info_tip->cchTextMax)) {
+        tooltip.erase(info_tip->cchTextMax - 2);  // Ellipsis + '\0'
+        const wchar_t kEllipsis = L'\x2026';
+        tooltip += kEllipsis;
+      }
+      if (!tooltip.empty())
+        wcscpy_s(info_tip->pszText, tooltip.length() + 1, tooltip.c_str());
+      return 1;
+    }
+
     default:
       break;
   }