Rebuild CFDE_TextEditEngine.

This CL rebuilds the text edit engine in a simpler fashion. Instead of
depending on multiple pages, paragraphs and buffer fields there is a
single text edit engine which contains a gap buffer.

This makes the code easier to understand and follow.

Change-Id: I10fe85603fa9ed15a647eaac2d931f113cd0c7b0
Reviewed-on: https://pdfium-review.googlesource.com/11990
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>

1 files changed, 418 insertions, 0 deletions

diff --git a/xfa/fde/cfde_texteditengine_unittest.cpp b/xfa/fde/cfde_texteditengine_unittest.cpp
new file mode 100644
index 0000000000..da11e46daa
--- /dev/null
+++ b/xfa/fde/cfde_texteditengine_unittest.cpp
@@ -0,0 +1,418 @@
+// Copyright 2017 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "xfa/fde/cfde_texteditengine.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/test_support.h"
+#include "third_party/base/ptr_util.h"
+
+class CFDE_TextEditEngineTest : public testing::Test {
+ public:
+  class Delegate : public CFDE_TextEditEngine::Delegate {
+   public:
+    void Reset() {
+      text_is_full = false;
+      fail_validation = false;
+    }
+
+    void NotifyTextFull() override { text_is_full = true; }
+
+    void OnCaretChanged() override {}
+    void OnTextChanged(const CFX_WideString& prevText) override {}
+    void OnSelChanged() override {}
+    bool OnValidate(const CFX_WideString& wsText) override {
+      return !fail_validation;
+    }
+    void SetScrollOffset(float fScrollOffset) override {}
+
+    bool fail_validation = false;
+    bool text_is_full = false;
+  };
+
+  CFDE_TextEditEngineTest() {}
+  ~CFDE_TextEditEngineTest() override {}
+
+  void SetUp() override {
+    font_ =
+        CFGAS_GEFont::LoadFont(L"Arial Black", 0, 0, GetGlobalFontManager());
+    ASSERT(font_.Get() != nullptr);
+
+    engine_ = pdfium::MakeUnique<CFDE_TextEditEngine>();
+    engine_->SetFont(font_);
+    engine_->SetFontSize(12.0f);
+  }
+
+  void TearDown() override { engine_.reset(); }
+
+  CFDE_TextEditEngine* engine() const { return engine_.get(); }
+
+ private:
+  CFX_RetainPtr<CFGAS_GEFont> font_;
+  std::unique_ptr<CFDE_TextEditEngine> engine_;
+};
+
+TEST_F(CFDE_TextEditEngineTest, Insert) {
+  EXPECT_STREQ(L"", engine()->GetText().c_str());
+
+  engine()->Insert(0, L"");
+  EXPECT_STREQ(L"", engine()->GetText().c_str());
+  EXPECT_EQ(0U, engine()->GetLength());
+
+  engine()->Insert(0, L"Hello");
+  EXPECT_STREQ(L"Hello", engine()->GetText().c_str());
+  EXPECT_EQ(5U, engine()->GetLength());
+
+  engine()->Insert(5, L" World");
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+  EXPECT_EQ(11U, engine()->GetLength());
+
+  engine()->Insert(5, L" New");
+  EXPECT_STREQ(L"Hello New World", engine()->GetText().c_str());
+
+  engine()->Insert(100, L" Cat");
+  EXPECT_STREQ(L"Hello New World Cat", engine()->GetText().c_str());
+
+  engine()->Clear();
+
+  engine()->SetHasCharacterLimit(true);
+  engine()->SetCharacterLimit(5);
+  engine()->Insert(0, L"Hello");
+
+  // No delegate
+  engine()->Insert(5, L" World");
+  EXPECT_STREQ(L"Hello", engine()->GetText().c_str());
+
+  engine()->SetCharacterLimit(8);
+  engine()->Insert(5, L" World");
+  EXPECT_STREQ(L"Hello Wo", engine()->GetText().c_str());
+
+  engine()->Clear();
+
+  // With Delegate
+  auto delegate = pdfium::MakeUnique<CFDE_TextEditEngineTest::Delegate>();
+  engine()->SetDelegate(delegate.get());
+
+  engine()->SetCharacterLimit(5);
+  engine()->Insert(0, L"Hello");
+
+  // Insert when full.
+  engine()->Insert(5, L" World");
+  EXPECT_TRUE(delegate->text_is_full);
+  EXPECT_STREQ(L"Hello", engine()->GetText().c_str());
+  delegate->Reset();
+
+  engine()->SetCharacterLimit(8);
+  engine()->Insert(5, L" World");
+  EXPECT_TRUE(delegate->text_is_full);
+  EXPECT_STREQ(L"Hello Wo", engine()->GetText().c_str());
+  delegate->Reset();
+  engine()->SetHasCharacterLimit(false);
+
+  engine()->Clear();
+  engine()->Insert(0, L"Hello");
+
+  // Insert Invalid text
+  delegate->fail_validation = true;
+  engine()->EnableValidation(true);
+  engine()->Insert(5, L" World");
+  EXPECT_STREQ(L"Hello", engine()->GetText().c_str());
+
+  delegate->fail_validation = false;
+  engine()->Insert(5, L" World");
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+  engine()->EnableValidation(false);
+
+  engine()->Clear();
+
+  engine()->Insert(0, L"Hello\nWorld");
+  EXPECT_FALSE(delegate->text_is_full);
+  EXPECT_STREQ(L"Hello\nWorld", engine()->GetText().c_str());
+  delegate->Reset();
+  engine()->Clear();
+
+  // Insert with limited area and over-fill
+  engine()->LimitHorizontalScroll(true);
+  engine()->SetAvailableWidth(60.0f);  // Fits 'Hello Wo'.
+  engine()->Insert(0, L"Hello");
+  EXPECT_FALSE(delegate->text_is_full);
+  engine()->Insert(5, L" World");
+  EXPECT_TRUE(delegate->text_is_full);
+  EXPECT_STREQ(L"Hello Wo", engine()->GetText().c_str());
+  engine()->LimitHorizontalScroll(false);
+
+  delegate->Reset();
+  engine()->Clear();
+
+  engine()->SetLineSpace(12.0f);
+  engine()->LimitVerticalScroll(true);
+  // Default is one line of text.
+  engine()->Insert(0, L"Hello");
+  EXPECT_FALSE(delegate->text_is_full);
+  engine()->Insert(5, L" Wo\nrld");
+  EXPECT_TRUE(delegate->text_is_full);
+  EXPECT_STREQ(L"Hello Wo\n", engine()->GetText().c_str());
+  engine()->LimitVerticalScroll(false);
+
+  engine()->SetDelegate(nullptr);
+}
+
+TEST_F(CFDE_TextEditEngineTest, Delete) {
+  EXPECT_STREQ(L"", engine()->Delete(0, 50).c_str());
+  EXPECT_STREQ(L"", engine()->GetText().c_str());
+
+  engine()->Insert(0, L"Hello World");
+  EXPECT_STREQ(L" World", engine()->Delete(5, 6).c_str());
+  EXPECT_STREQ(L"Hello", engine()->GetText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"Hello World");
+  EXPECT_STREQ(L" ", engine()->Delete(5, 1).c_str());
+  EXPECT_STREQ(L"HelloWorld", engine()->GetText().c_str());
+
+  EXPECT_STREQ(L"elloWorld", engine()->Delete(1, 50).c_str());
+  EXPECT_STREQ(L"H", engine()->GetText().c_str());
+}
+
+TEST_F(CFDE_TextEditEngineTest, Clear) {
+  EXPECT_STREQ(L"", engine()->GetText().c_str());
+
+  engine()->Clear();
+  EXPECT_STREQ(L"", engine()->GetText().c_str());
+
+  engine()->Insert(0, L"Hello World");
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+
+  engine()->Clear();
+  EXPECT_STREQ(L"", engine()->GetText().c_str());
+  EXPECT_EQ(0U, engine()->GetLength());
+}
+
+TEST_F(CFDE_TextEditEngineTest, GetChar) {
+  // Out of bounds.
+  EXPECT_EQ(L'\0', engine()->GetChar(0));
+
+  engine()->Insert(0, L"Hello World");
+  EXPECT_EQ(L'H', engine()->GetChar(0));
+  EXPECT_EQ(L'd', engine()->GetChar(engine()->GetLength() - 1));
+  EXPECT_EQ(L' ', engine()->GetChar(5));
+
+  engine()->Insert(5, L" A");
+  EXPECT_STREQ(L"Hello A World", engine()->GetText().c_str());
+  EXPECT_EQ(L'W', engine()->GetChar(8));
+
+  engine()->EnablePasswordMode(true);
+  EXPECT_EQ(L'*', engine()->GetChar(8));
+
+  engine()->SetAliasChar(L'+');
+  EXPECT_EQ(L'+', engine()->GetChar(8));
+}
+
+TEST_F(CFDE_TextEditEngineTest, GetWidthOfChar) {
+  // Out of Bounds.
+  EXPECT_EQ(0U, engine()->GetWidthOfChar(0));
+
+  engine()->Insert(0, L"Hello World");
+  EXPECT_EQ(199920U, engine()->GetWidthOfChar(0));
+  EXPECT_EQ(159840U, engine()->GetWidthOfChar(1));
+
+  engine()->Insert(0, L"\t");
+  EXPECT_EQ(0U, engine()->GetWidthOfChar(0));
+}
+
+TEST_F(CFDE_TextEditEngineTest, GetDisplayPos) {
+  EXPECT_EQ(0U, engine()->GetDisplayPos(FDE_TEXTEDITPIECE()).size());
+}
+
+TEST_F(CFDE_TextEditEngineTest, Selection) {
+  EXPECT_FALSE(engine()->HasSelection());
+  engine()->SelectAll();
+  EXPECT_FALSE(engine()->HasSelection());
+
+  engine()->Insert(0, L"Hello World");
+  EXPECT_STREQ(L"", engine()->DeleteSelectedText().c_str());
+
+  EXPECT_FALSE(engine()->HasSelection());
+  engine()->SelectAll();
+  EXPECT_TRUE(engine()->HasSelection());
+  EXPECT_STREQ(L"Hello World", engine()->GetSelectedText().c_str());
+
+  engine()->ClearSelection();
+  EXPECT_FALSE(engine()->HasSelection());
+  EXPECT_STREQ(L"", engine()->GetSelectedText().c_str());
+
+  engine()->SelectAll();
+  size_t start_idx;
+  size_t end_idx;
+  std::tie(start_idx, end_idx) = engine()->GetSelection();
+  EXPECT_EQ(0U, start_idx);
+  EXPECT_EQ(10U, end_idx);
+
+  // Selection before gap.
+  EXPECT_STREQ(L"Hello World", engine()->GetSelectedText().c_str());
+  EXPECT_TRUE(engine()->HasSelection());
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+
+  engine()->Insert(5, L" A");
+  EXPECT_FALSE(engine()->HasSelection());
+  EXPECT_STREQ(L"", engine()->GetSelectedText().c_str());
+
+  // Selection over the gap.
+  engine()->SelectAll();
+  EXPECT_TRUE(engine()->HasSelection());
+  EXPECT_STREQ(L"Hello A World", engine()->GetSelectedText().c_str());
+  engine()->Clear();
+
+  engine()->Insert(0, L"Hello World");
+  engine()->SelectAll();
+
+  EXPECT_STREQ(L"Hello World", engine()->DeleteSelectedText().c_str());
+  EXPECT_FALSE(engine()->HasSelection());
+  EXPECT_STREQ(L"", engine()->GetText().c_str());
+
+  engine()->Insert(0, L"Hello World");
+  engine()->SetSelection(5, 9);
+  EXPECT_STREQ(L" Worl", engine()->DeleteSelectedText().c_str());
+  EXPECT_FALSE(engine()->HasSelection());
+  EXPECT_STREQ(L"Hellod", engine()->GetText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"Hello World");
+  engine()->SelectAll();
+  engine()->ReplaceSelectedText(L"Goodbye Everybody");
+  EXPECT_FALSE(engine()->HasSelection());
+  EXPECT_STREQ(L"Goodbye Everybody", engine()->GetText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"Hello World");
+  engine()->SetSelection(1, 4);
+  engine()->ReplaceSelectedText(L"i,");
+  EXPECT_FALSE(engine()->HasSelection());
+  EXPECT_STREQ(L"Hi, World", engine()->GetText().c_str());
+
+  // Selection fully after gap.
+  engine()->Clear();
+  engine()->Insert(0, L"Hello");
+  engine()->Insert(0, L"A ");
+  engine()->SetSelection(3, 6);
+  EXPECT_STREQ(L"ello", engine()->GetSelectedText().c_str());
+
+  engine()->Clear();
+  engine()->Insert(0, L"Hello World");
+  engine()->ClearSelection();
+  engine()->DeleteSelectedText();
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+}
+
+TEST_F(CFDE_TextEditEngineTest, UndoRedo) {
+  EXPECT_FALSE(engine()->CanUndo());
+  EXPECT_FALSE(engine()->CanRedo());
+  EXPECT_FALSE(engine()->Undo());
+  EXPECT_FALSE(engine()->Redo());
+
+  engine()->Insert(0, L"Hello");
+  EXPECT_TRUE(engine()->CanUndo());
+  EXPECT_FALSE(engine()->CanRedo());
+  EXPECT_TRUE(engine()->Undo());
+  EXPECT_STREQ(L"", engine()->GetText().c_str());
+  EXPECT_FALSE(engine()->CanUndo());
+  EXPECT_TRUE(engine()->CanRedo());
+  EXPECT_TRUE(engine()->Redo());
+  EXPECT_STREQ(L"Hello", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->CanUndo());
+  EXPECT_FALSE(engine()->CanRedo());
+
+  engine()->Clear();
+  EXPECT_FALSE(engine()->CanUndo());
+  EXPECT_FALSE(engine()->CanRedo());
+
+  engine()->Insert(0, L"Hello World");
+  engine()->SelectAll();
+  engine()->DeleteSelectedText();
+  EXPECT_STREQ(L"", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->CanUndo());
+  EXPECT_TRUE(engine()->Undo());
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->CanRedo());
+  EXPECT_TRUE(engine()->Redo());
+  EXPECT_STREQ(L"", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->CanUndo());
+  EXPECT_FALSE(engine()->CanRedo());
+
+  engine()->Insert(0, L"Hello World");
+  engine()->SelectAll();
+  engine()->ReplaceSelectedText(L"Goodbye Friend");
+  EXPECT_STREQ(L"Goodbye Friend", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->CanUndo());
+  EXPECT_TRUE(engine()->Undo());
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->CanRedo());
+  EXPECT_TRUE(engine()->Redo());
+  EXPECT_STREQ(L"Goodbye Friend", engine()->GetText().c_str());
+
+  engine()->Clear();
+  engine()->SetMaxEditOperationsForTesting(3);
+  engine()->Insert(0, L"First ");
+  engine()->Insert(engine()->GetLength(), L"Second ");
+  engine()->Insert(engine()->GetLength(), L"Third");
+
+  EXPECT_TRUE(engine()->CanUndo());
+  EXPECT_TRUE(engine()->Undo());
+  EXPECT_STREQ(L"First Second ", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->CanUndo());
+  EXPECT_TRUE(engine()->Undo());
+  EXPECT_FALSE(
+      engine()->CanUndo());  // Can't undo First; undo buffer too small.
+  EXPECT_STREQ(L"First ", engine()->GetText().c_str());
+
+  EXPECT_TRUE(engine()->CanRedo());
+  EXPECT_TRUE(engine()->Redo());
+  EXPECT_TRUE(engine()->CanRedo());
+  EXPECT_TRUE(engine()->Redo());
+  EXPECT_FALSE(engine()->CanRedo());
+  EXPECT_STREQ(L"First Second Third", engine()->GetText().c_str());
+
+  engine()->Clear();
+
+  engine()->SetMaxEditOperationsForTesting(4);
+
+  // Go beyond the max operations limit.
+  engine()->Insert(0, L"H");
+  engine()->Insert(1, L"e");
+  engine()->Insert(2, L"l");
+  engine()->Insert(3, L"l");
+  engine()->Insert(4, L"o");
+  engine()->Insert(5, L" World");
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+
+  // Do A, undo. Do B, undo. Redo should cause B.
+  engine()->Delete(4, 3);
+  EXPECT_STREQ(L"Hellorld", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->Undo());
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+  engine()->Delete(5, 6);
+  EXPECT_STREQ(L"Hello", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->Undo());
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->Redo());
+  EXPECT_STREQ(L"Hello", engine()->GetText().c_str());
+
+  // Undo down to the limit.
+  EXPECT_TRUE(engine()->Undo());
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->Undo());
+  EXPECT_STREQ(L"Hello", engine()->GetText().c_str());
+  EXPECT_TRUE(engine()->Undo());
+  EXPECT_STREQ(L"Hell", engine()->GetText().c_str());
+  EXPECT_FALSE(engine()->Undo());
+  EXPECT_STREQ(L"Hell", engine()->GetText().c_str());
+}
+
+TEST_F(CFDE_TextEditEngineTest, GetIndexForPoint) {
+  engine()->SetFontSize(10.0f);
+  engine()->Insert(0, L"Hello World");
+  EXPECT_EQ(0U, engine()->GetIndexForPoint({0.0f, 0.0f}));
+  EXPECT_EQ(11U, engine()->GetIndexForPoint({999999.0f, 9999999.0f}));
+  EXPECT_EQ(1U, engine()->GetIndexForPoint({10.0f, 5.0f}));
+}