Implement word selection in CFDE_TextEditEngine

This CL implements the needed logic in CFDE_TextEditEngine to handle
word selection.

Change-Id: I6b388c23655037fec107d68ec07d33638b959374
Reviewed-on: https://pdfium-review.googlesource.com/13211
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>

3 files changed, 136 insertions, 7 deletions

diff --git a/xfa/fde/cfde_texteditengine.cpp b/xfa/fde/cfde_texteditengine.cpp
index e92897ea7d..b5948d45ce 100644
--- a/xfa/fde/cfde_texteditengine.cpp
+++ b/xfa/fde/cfde_texteditengine.cpp
@@ -9,6 +9,7 @@
 #include <algorithm>
 #include <limits>
 
+#include "core/fxcrt/cfx_wordbreak.h"
 #include "xfa/fde/cfde_textout.h"
 
 namespace {
@@ -927,7 +928,14 @@ std::vector<CFX_RectF> CFDE_TextEditEngine::GetCharacterRectsInRange(
   return rects;
 }
 
-CFDE_TextEditEngine::Iterator::Iterator(CFDE_TextEditEngine* engine)
+std::pair<size_t, size_t> CFDE_TextEditEngine::BoundsForWordAt(
+    size_t idx) const {
+  CFX_WordBreak breaker(
+      pdfium::MakeUnique<CFDE_TextEditEngine::Iterator>(this));
+  return breaker.BoundsAt(idx);
+}
+
+CFDE_TextEditEngine::Iterator::Iterator(const CFDE_TextEditEngine* engine)
     : engine_(engine), current_position_(-1) {}
 
 CFDE_TextEditEngine::Iterator::~Iterator() {}
@@ -936,8 +944,9 @@ bool CFDE_TextEditEngine::Iterator::Next(bool bPrev) {
   if (bPrev && current_position_ == -1)
     return false;
   if (!bPrev && current_position_ > -1 &&
-      static_cast<size_t>(current_position_) == engine_->GetLength())
+      static_cast<size_t>(current_position_) == engine_->GetLength()) {
     return false;
+  }
 
   if (bPrev)
     --current_position_;
@@ -952,7 +961,12 @@ wchar_t CFDE_TextEditEngine::Iterator::GetChar() const {
 }
 
 void CFDE_TextEditEngine::Iterator::SetAt(int32_t nIndex) {
-  NOTREACHED();
+  if (nIndex < 0)
+    current_position_ = 0;
+  else if (static_cast<size_t>(nIndex) >= engine_->GetLength())
+    current_position_ = engine_->GetLength();
+  else
+    current_position_ = nIndex;
 }
 
 int32_t CFDE_TextEditEngine::Iterator::GetAt() const {
@@ -967,6 +981,7 @@ bool CFDE_TextEditEngine::Iterator::IsEOF(bool bTail) const {
 }
 
 std::unique_ptr<IFX_CharIter> CFDE_TextEditEngine::Iterator::Clone() const {
-  NOTREACHED();
-  return pdfium::MakeUnique<CFDE_TextEditEngine::Iterator>(engine_.Get());
+  auto it = pdfium::MakeUnique<CFDE_TextEditEngine::Iterator>(engine_.Get());
+  it->current_position_ = current_position_;
+  return it;
 }
diff --git a/xfa/fde/cfde_texteditengine.h b/xfa/fde/cfde_texteditengine.h
index 35d9664f99..0277b0cc64 100644
--- a/xfa/fde/cfde_texteditengine.h
+++ b/xfa/fde/cfde_texteditengine.h
@@ -40,7 +40,7 @@ class CFDE_TextEditEngine {
  public:
   class Iterator : public IFX_CharIter {
    public:
-    explicit Iterator(CFDE_TextEditEngine* engine);
+    explicit Iterator(const CFDE_TextEditEngine* engine);
     ~Iterator() override;
 
     bool Next(bool bPrev = false) override;
@@ -51,7 +51,7 @@ class CFDE_TextEditEngine {
     std::unique_ptr<IFX_CharIter> Clone() const override;
 
    private:
-    CFX_UnownedPtr<CFDE_TextEditEngine> engine_;
+    CFX_UnownedPtr<const CFDE_TextEditEngine> engine_;
     int32_t current_position_;
   };
 
@@ -160,6 +160,8 @@ class CFDE_TextEditEngine {
   size_t GetWidthOfChar(size_t idx);
   // Non-const so we can force a Layout() if needed.
   size_t GetIndexForPoint(const CFX_PointF& point);
+  // <start_idx, end_idx>
+  std::pair<size_t, size_t> BoundsForWordAt(size_t idx) const;
 
   // Returns <bidi level, character rect>
   std::pair<int32_t, CFX_RectF> GetCharacterInfo(int32_t start_idx);
diff --git a/xfa/fde/cfde_texteditengine_unittest.cpp b/xfa/fde/cfde_texteditengine_unittest.cpp
index da11e46daa..2084914bbf 100644
--- a/xfa/fde/cfde_texteditengine_unittest.cpp
+++ b/xfa/fde/cfde_texteditengine_unittest.cpp
@@ -416,3 +416,115 @@ TEST_F(CFDE_TextEditEngineTest, GetIndexForPoint) {
   EXPECT_EQ(11U, engine()->GetIndexForPoint({999999.0f, 9999999.0f}));
   EXPECT_EQ(1U, engine()->GetIndexForPoint({10.0f, 5.0f}));
 }
+
+TEST_F(CFDE_TextEditEngineTest, BoundsForWordAt) {
+  size_t start_idx;
+  size_t end_idx;
+
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(100);
+  EXPECT_EQ(0U, start_idx);
+  EXPECT_EQ(0U, end_idx);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"", engine()->GetSelectedText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"Hello");
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(0);
+  EXPECT_EQ(0U, start_idx);
+  EXPECT_EQ(4U, end_idx);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"Hello", engine()->GetSelectedText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"Hello World");
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(100);
+  EXPECT_EQ(11U, start_idx);
+  EXPECT_EQ(11U, end_idx);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"", engine()->GetSelectedText().c_str());
+
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(0);
+  EXPECT_EQ(0U, start_idx);
+  EXPECT_EQ(4U, end_idx);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"Hello", engine()->GetSelectedText().c_str());
+
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(1);
+  EXPECT_EQ(0U, start_idx);
+  EXPECT_EQ(4U, end_idx);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"Hello", engine()->GetSelectedText().c_str());
+
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(4);
+  EXPECT_EQ(0U, start_idx);
+  EXPECT_EQ(4U, end_idx);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"Hello", engine()->GetSelectedText().c_str());
+
+  // Select the space
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(5);
+  EXPECT_EQ(5U, start_idx);
+  EXPECT_EQ(5U, end_idx);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"", engine()->GetSelectedText().c_str());
+
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(6);
+  EXPECT_EQ(6U, start_idx);
+  EXPECT_EQ(10U, end_idx);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"World", engine()->GetSelectedText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"123 456 789");
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(5);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"456", engine()->GetSelectedText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"123def789");
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(5);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"123def789", engine()->GetSelectedText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"abc456ghi");
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(5);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"abc456ghi", engine()->GetSelectedText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"hello, world");
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(0);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"hello", engine()->GetSelectedText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"hello, world");
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(5);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"", engine()->GetSelectedText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"np-complete");
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(6);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"complete", engine()->GetSelectedText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"(123) 456-7890");
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(0);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"", engine()->GetSelectedText().c_str());
+
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(1);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"123", engine()->GetSelectedText().c_str());
+
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(7);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"456", engine()->GetSelectedText().c_str());
+
+  std::tie(start_idx, end_idx) = engine()->BoundsForWordAt(11);
+  engine()->SetSelection(start_idx, end_idx);
+  EXPECT_STREQ(L"7890", engine()->GetSelectedText().c_str());
+}