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// Copyright (c) 2006-2008 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/controls/combo_box.h"
#include "app/gfx/chrome_canvas.h"
#include "app/gfx/chrome_font.h"
#include "app/l10n_util.h"
#include "app/resource_bundle.h"
#include "base/gfx/native_theme.h"
#include "base/gfx/rect.h"
// Limit how small a combobox can be.
static const int kMinComboboxWidth = 148;
// Add a couple extra pixels to the widths of comboboxes and combobox
// dropdowns so that text isn't too crowded.
static const int kComboboxExtraPaddingX = 6;
namespace views {
ComboBox::ComboBox(Model* model)
: model_(model), selected_item_(0), listener_(NULL), content_width_(0) {
}
ComboBox::~ComboBox() {
}
void ComboBox::SetListener(Listener* listener) {
listener_ = listener;
}
gfx::Size ComboBox::GetPreferredSize() {
HWND hwnd = GetNativeControlHWND();
if (!hwnd)
return gfx::Size();
COMBOBOXINFO cbi;
memset(reinterpret_cast<unsigned char*>(&cbi), 0, sizeof(cbi));
cbi.cbSize = sizeof(cbi);
// Note: Don't use CB_GETCOMBOBOXINFO since that crashes on WOW64 systems
// when you have a global message hook installed.
GetComboBoxInfo(hwnd, &cbi);
gfx::Rect rect_item(cbi.rcItem);
gfx::Rect rect_button(cbi.rcButton);
gfx::Size border = gfx::NativeTheme::instance()->GetThemeBorderSize(
gfx::NativeTheme::MENULIST);
// The padding value of '3' is the xy offset from the corner of the control
// to the corner of rcItem. It does not seem to be queryable from the theme.
// It is consistent on all versions of Windows from 2K to Vista, and is
// invariant with respect to the combobox border size. We could conceivably
// get this number from rect_item.x, but it seems fragile to depend on
// position here, inside of the layout code.
const int kItemOffset = 3;
int item_to_button_distance = std::max(kItemOffset - border.width(), 0);
// The cx computation can be read as measuring from left to right.
int pref_width = std::max(kItemOffset + content_width_ +
kComboboxExtraPaddingX +
item_to_button_distance + rect_button.width() +
border.width(), kMinComboboxWidth);
// The two arguments to ::max below should be typically be equal.
int pref_height = std::max(rect_item.height() + 2 * kItemOffset,
rect_button.height() + 2 * border.height());
return gfx::Size(pref_width, pref_height);
}
// VK_ESCAPE should be handled by this view when the drop down list is active.
// In other words, the list should be closed instead of the dialog.
bool ComboBox::OverrideAccelerator(const Accelerator& accelerator) {
if (accelerator != Accelerator(VK_ESCAPE, false, false, false))
return false;
HWND hwnd = GetNativeControlHWND();
if (!hwnd)
return false;
return ::SendMessage(hwnd, CB_GETDROPPEDSTATE, 0, 0) != 0;
}
HWND ComboBox::CreateNativeControl(HWND parent_container) {
HWND r = ::CreateWindowEx(GetAdditionalExStyle(), L"COMBOBOX", L"",
WS_CHILD | WS_VSCROLL | CBS_DROPDOWNLIST,
0, 0, width(), height(),
parent_container, NULL, NULL, NULL);
HFONT font = ResourceBundle::GetSharedInstance().
GetFont(ResourceBundle::BaseFont).hfont();
SendMessage(r, WM_SETFONT, reinterpret_cast<WPARAM>(font), FALSE);
UpdateComboBoxFromModel(r);
return r;
}
LRESULT ComboBox::OnCommand(UINT code, int id, HWND source) {
HWND hwnd = GetNativeControlHWND();
if (!hwnd)
return 0;
if (code == CBN_SELCHANGE && source == hwnd) {
LRESULT r = ::SendMessage(hwnd, CB_GETCURSEL, 0, 0);
if (r != CB_ERR) {
int prev_selected_item = selected_item_;
selected_item_ = static_cast<int>(r);
if (listener_)
listener_->ItemChanged(this, prev_selected_item, selected_item_);
}
}
return 0;
}
LRESULT ComboBox::OnNotify(int w_param, LPNMHDR l_param) {
return 0;
}
void ComboBox::UpdateComboBoxFromModel(HWND hwnd) {
::SendMessage(hwnd, CB_RESETCONTENT, 0, 0);
gfx::Font font = ResourceBundle::GetSharedInstance().GetFont(
ResourceBundle::BaseFont);
int max_width = 0;
int num_items = model_->GetItemCount(this);
for (int i = 0; i < num_items; ++i) {
const std::wstring& text = model_->GetItemAt(this, i);
// Inserting the Unicode formatting characters if necessary so that the
// text is displayed correctly in right-to-left UIs.
std::wstring localized_text;
const wchar_t* text_ptr = text.c_str();
if (l10n_util::AdjustStringForLocaleDirection(text, &localized_text))
text_ptr = localized_text.c_str();
::SendMessage(hwnd, CB_ADDSTRING, 0, reinterpret_cast<LPARAM>(text_ptr));
max_width = std::max(max_width, font.GetStringWidth(text));
}
content_width_ = max_width;
if (num_items > 0) {
::SendMessage(hwnd, CB_SETCURSEL, selected_item_, 0);
// Set the width for the drop down while accounting for the scrollbar and
// borders.
if (num_items > ComboBox_GetMinVisible(hwnd))
max_width += ::GetSystemMetrics(SM_CXVSCROLL);
// SM_CXEDGE would not be correct here, since the dropdown is flat, not 3D.
int kComboboxDropdownBorderSize = 1;
max_width += 2 * kComboboxDropdownBorderSize + kComboboxExtraPaddingX;
::SendMessage(hwnd, CB_SETDROPPEDWIDTH, max_width, 0);
}
}
void ComboBox::ModelChanged() {
HWND hwnd = GetNativeControlHWND();
if (!hwnd)
return;
selected_item_ = std::min(0, model_->GetItemCount(this));
UpdateComboBoxFromModel(hwnd);
}
void ComboBox::SetSelectedItem(int index) {
selected_item_ = index;
HWND hwnd = GetNativeControlHWND();
if (!hwnd)
return;
// Note that we use CB_SETCURSEL and not CB_SELECTSTRING because on RTL
// locales the strings we get from our ComboBox::Model might be augmented
// with Unicode directionality marks before we insert them into the combo box
// and therefore we can not assume that the string we get from
// ComboBox::Model can be safely searched for and selected (which is what
// CB_SELECTSTRING does).
::SendMessage(hwnd, CB_SETCURSEL, selected_item_, 0);
}
int ComboBox::GetSelectedItem() {
return selected_item_;
}
} // namespace views
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