// Copyright (c) 2009 The Chromium 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 "views/widget/tooltip_manager.h"

#include <vector>

#include "app/gfx/text_elider.h"

namespace views {

// Maximum number of characters we allow in a tooltip.
static const size_t kMaxTooltipLength = 1024;

// Maximum number of lines we allow in the tooltip.
static const size_t kMaxLines = 6;

// Breaks |text| along line boundaries, placing each line of text into lines.
static void SplitTooltipString(const std::wstring& text,
                               std::vector<std::wstring>* lines) {
  size_t index = 0;
  size_t next_index;
  while ((next_index = text.find(TooltipManager::GetLineSeparator(), index))
         != std::wstring::npos && lines->size() < kMaxLines) {
    lines->push_back(text.substr(index, next_index - index));
    index = next_index + TooltipManager::GetLineSeparator().size();
  }
  if (next_index != text.size() && lines->size() < kMaxLines)
    lines->push_back(text.substr(index, text.size() - index));
}

// static
void TooltipManager::TrimTooltipToFit(std::wstring* text,
                                      int* max_width,
                                      int* line_count,
                                      int x,
                                      int y) {
  *max_width = 0;
  *line_count = 0;

  // Clamp the tooltip length to kMaxTooltipLength so that we don't
  // accidentally DOS the user with a mega tooltip.
  if (text->length() > kMaxTooltipLength)
    *text = text->substr(0, kMaxTooltipLength);

  // Determine the available width for the tooltip.
  int available_width = GetMaxWidth(x, y);

  // Split the string.
  std::vector<std::wstring> lines;
  SplitTooltipString(*text, &lines);
  *line_count = static_cast<int>(lines.size());

  // Format each line to fit.
  gfx::Font font = GetDefaultFont();
  std::wstring result;
  for (std::vector<std::wstring>::iterator i = lines.begin(); i != lines.end();
       ++i) {
    std::wstring elided_text = gfx::ElideText(*i, font, available_width);
    *max_width = std::max(*max_width, font.GetStringWidth(elided_text));
    if (i == lines.begin() && i + 1 == lines.end()) {
      *text = elided_text;
      return;
    }
    if (!result.empty())
      result.append(GetLineSeparator());
    result.append(elided_text);
  }
  *text = result;
}

}  // namespace views